算法设计与分析第2版吕国英第三章课后习题答案
算法设计与分析第二版课后习题解答
算法设计与分析第二版课后习题解答算法设计与分析基础课后练习答案习题 4.设计一个计算的算法，n是任意正整数。
除了赋值和比较运算，该算法只能用到基本的四则运算操作。
算法求//输入：一个正整数n2//输出：。
step1:a=1；step2:若a*a 5. a．用欧几里德算法求gcd。
b. 用欧几里德算法求gcd,比检查min｛m，n｝和gcd间连续整数的算法快多少倍？请估算一下。
a. gcd(31415, 14142) = gcd(14142, 3131) = gcd(3131, 1618) =gcd(1618, 1513) = gcd(1513,105) = gcd(1513, 105) = gcd(105, 43) =gcd(43, 19) = gcd(19, 5) = gcd(5, 4) = gcd(4, 1) = gcd(1, 0) = 1.b.有a可知计算gcd欧几里德算法做了11次除法。
连续整数检测算法在14142每次迭代过程中或者做了一次除法，或者两次除法，因此这个算法做除法的次数鉴于1·14142 和 2·14142之间，所以欧几里德算法比此算法快1·14142/11 ≈ 1300 与 2·14142/11 ≈ 2600 倍之间。
6.证明等式gcd(m,n)=gcd(n,m mod n)对每一对正整数m,n都成立. Hint:根据除法的定义不难证明:如果d整除u和v, 那么d一定能整除u±v;如果d整除u,那么d也能够整除u的任何整数倍ku.对于任意一对正整数m,n,若d能整除m和n,那么d一定能整除n和r=m mod n=m-qn；显然，若d能整除n和r，也一定能整除m=r+qn和n。
数对(m,n)和(n,r)具有相同的公约数的有限非空集，其中也包括了最大公约数。
故gcd(m,n)=gcd(n,r)7.对于第一个数小于第二个数的一对数字,欧几里得算法将会如何处理?该算法在处理这种输入的过程中,上述情况最多会发生几次? Hint:对于任何形如0 gcd(m,n)=gcd(n,m)并且这种交换处理只发生一次.对于所有1≤m,n≤10的输入, Euclid算法最少要做几次除法?(1次) b. 对于所有1≤m,n≤10的输入, Euclid算法最多要做几次除法?(5次) gcd(5,8) 习题 1.(农夫过河)P—农夫 W—狼G—山羊C—白菜 2.(过桥问题)1,2,5,10---分别代表4个人, f—手电筒4. 对于任意实系数a,b,c, 某个算法能求方程ax^2+bx+c=0的实根,写出上述算法的伪代码(可以假设sqrt(x)是求平方根的函数) 算法Quadratic(a,b,c)//求方程ax^2+bx+c=0的实根的算法 //输入:实系数a,b,c//输出:实根或者无解信息 If a≠0D←b*b-4*a*c If D>0temp←2*ax1←(-b+sqrt(D))/temp x2←(-b-sqrt(D))/temp return x1,x2else if D=0 return –b/(2*a) else return “no real roots” else //a=0if b≠0 return –c/b else //a=b=0if c=0 return “no real numbers”else return “no real roots”5. 描述将十进制整数表达为二进制整数的标准算法 a.用文字描述 b.用伪代码描述解答：a.将十进制整数转换为二进制整数的算法输入：一个正整数n输出：正整数n相应的二进制数第一步：用n除以2，余数赋给Ki(i=0,1,2...)，商赋给n 第二步：如果n=0，则到第三步，否则重复第一步第三步：将Ki按照i从高到低的顺序输出 b.伪代码算法 DectoBin(n)//将十进制整数n转换为二进制整数的算法 //输入：正整数n//输出：该正整数相应的二进制数，该数存放于数组Bin[1...n]中 i=1while n!=0 do { Bin[i]=n%2; n=(int)n/2; i++; } while i!=0 do{ print Bin[i]; i--; }9.考虑下面这个算法,它求的是数组中大小相差最小的两个元素的差.(算法略) 对这个算法做尽可能多的改进. 算法 MinDistance(A[0..n-1]) //输入:数组A[0..n-1] //输出:the smallest distance d between two of its elements习题1. 考虑这样一个排序算法,该算法对于待排序的数组中的每一个元素,计算比它小的元素个数,然后利用这个信息,将各个元素放到有序数组的相应位置上去.a.应用该算法对列表”60,35,81,98,14,47”排序b.该算法稳定吗?c.该算法在位吗? 解:a. 该算法对列表”60,35,81,98,14,47”排序的过程如下所示:b.该算法不稳定.比如对列表”2,2*”排序c.该算法不在位.额外空间for S and Count 4.(古老的七桥问题) 第2章习题7.对下列断言进行证明:(如果是错误的,请举例) a. 如果t(n)∈O(g(n),则g(n)∈Ω(t(n)) b.α>0时,Θ(αg(n))= Θ(g(n)) 解:a. 这个断言是正确的。
算法设计与分析习题解答
第一章作业1.证明下列Ο、Ω和Θ的性质1）f=Ο(g)当且仅当g=Ω(f)证明：充分性。
若f=Ο(g)，则必然存在常数c1>0和n0，使得∀n≥n0，有f≤c1*g(n)。
由于c1≠0，故g(n) ≥ 1/ c1 *f(n)，故g=Ω(f)。
必要性。
同理，若g=Ω(f)，则必然存在c2>0和n0，使得∀n≥n0，有g(n) ≥ c2 *f(n).由于c2≠0，故f(n) ≤ 1/ c2*f(n)，故f=Ο(g)。
2）若f=Θ(g)则g=Θ(f)证明：若f=Θ(g)，则必然存在常数c1>0，c2>0和n0，使得∀n≥n0，有c1*g(n) ≤f(n) ≤ c2*g(n)。
由于c1≠0，c2≠0，f(n) ≥c1*g(n)可得g(n) ≤ 1/c1*f(n)，同时，f(n) ≤c2*g(n)，有g(n) ≥ 1/c2*f(n)，即1/c2*f(n) ≤g(n) ≤ 1/c1*f(n)，故g=Θ(f)。
3）Ο(f+g)= Ο(max(f,g))，对于Ω和Θ同样成立。
证明：设F(n)= Ο(f+g)，则存在c1>0，和n1，使得∀n≥n1，有F(n) ≤ c1 (f(n)+g(n))= c1 f(n) + c1g(n)≤ c1*max{f,g}+ c1*max{f,g}=2 c1*max{f,g}所以，F(n)=Ο(max(f,g))，即Ο(f+g)= Ο(max(f,g))对于Ω和Θ同理证明可以成立。
4）log(n!)= Θ(nlogn)证明：∙由于log(n!)=∑=n i i 1log ≤∑=ni n 1log =nlogn ，所以可得log(n!)= Ο(nlogn)。
∙由于对所有的偶数n 有，log(n!)= ∑=n i i 1log ≥∑=n n i i 2/log ≥∑=nn i n 2/2/log ≥(n/2)log(n/2)=(nlogn)/2-n/2。
当n ≥4，(nlogn)/2-n/2≥(nlogn)/4，故可得∀n ≥4，log(n!) ≥(nlogn)/4，即log(n!)= Ω(nlogn)。
Python程序设计与算法基础教程（第二版）微课版第三章上机实践答案
Python程序设计与算法基础教程（第⼆版）微课版第三章上机实践答案Python程序设计与算法基础教程（第⼆版）微课版第三章上机实践答案2.Sum =0for i in range(1,101):Sum += iprint("1+2+3+...+100 = ", Sum)3.Sum =0for i in range(10,0,-1):Sum += iprint("10+9+8+...+1 = ", Sum)4.Sum =0for i in range(1,100,2):Sum += iprint("1+3+5+7+...+99 = ", Sum)5.Sum =0for i in range(2,101,2):Sum += iprint("2+4+6+8+...+100 = ", Sum)6.n =0for i in range(2000,3001):if((i %4==0and i %100!=0)or(i %400==0)):print(i, end =' ')n +=1if(n %10==0):print()7.i =1S =0for n in range(1,100):if(n %2!=0):if(i %2==0):n =-(i *2-1)else:n =( i *2-1)i +=1S += nprint("1-3+5-7+9-11+... = ", S)8.S =0for i in range(1,101):n =1.0/ iS += nprint(str.format("1+1/2+1/3+... = {0: .2f}", S))9.打印上三⾓九九乘法表：for a in range(1,10):for b in range(1, a+1):print(str.format("{0:2} * {1:2} = {2:>2}", a, b, a*b), end =' ')print()打印矩形块九九乘法表：for a in range(1,10):for b in range(1,10):print(str.format("{0:>2} * {1:1} = {2:>2}", a, b, a*b), end =' ')print()打印下三⾓九九乘法表:for a in range(1,10):for b in range(1,10):if(b < a):print(end =' ')else:print(str.format("{0:2} * {1:1} = {2:>2}", a, b, a*b), end =' ')print()10.import matha =float(input("请输⼊三⾓形的边a :"))b =float(input("请输⼊三⾓形的边b :"))c =float(input("请输⼊三⾓形的边c :"))if(a >0and b >0and c >0and a + b > c and a + c > b and b + c > a):h =1/2*(a+b+c)print(str.format("三⾓形的三条边分别为：a = {0} b = {1} c = {2}", a, b, c))print(str.format("三⾓形的周长 = {0} ⾯积 = {1}", a+b+c, math.sqrt(h *(h-a)*(h-b)*(h-c)))) else:print("⽆法构成三⾓形！")11.⽅法⼀（单分⽀语句）：import mathx =float(input("请输⼊x："))print("⽅法⼀（单分⽀语句）：")if(x >=0):y =(x**2-3*x)/(x +1)+2*math.pi + math.sin(x)if(x <0):y = math.log(-5*x)+6* math.sqrt(abs(x)+pow(math.e,4))-pow((x +1),3)print(str.format("x = {0}, y = {1}", x, y))⽅法⼆（双分⽀结构）：import mathx =float(input("请输⼊x："))if(x >=0):y =(x**2-3*x)/(x +1)+2*math.pi + math.sin(x)else:y = math.log(-5*x)+6* math.sqrt(abs(x)+pow(math.e,4))-pow((x +1),3)print(str.format("x = {0}, y = {1}", x, y))⽅法三（条件运算语句）：x =float(input("请输⼊x："))y =(x**2-3*x)/(x +1)+2*math.pi + math.sin(x)if(x >=0) \else math.log(-5*x)+6* math.sqrt(abs(x)+pow(math.e,4))-pow((x +1),3)print(str.format("x = {0}, y = {1}", x, y))12.import matha =float(input("请输⼊系数a : "))b =float(input("请输⼊系数b : "))c =float(input("请输⼊系数c : "))delt = b**2-4*a*cif(a ==0and b ==0):print("此⽅程⽆解！")elif(a ==0and b !=0):print(str.format("此⽅程的解为：{0: .1f}",-c / b))elif(b**2-4*a*c ==0):print(str.format("此⽅程有两个相等虚根：{0:.1f}",-b /(2*a)))elif(delt >0):print(str.format("此⽅程有两个不等虚根: {0:.1f} 和 {1:.1f}",(-b + math.sqrt(delt))/(2*a),(-b - math.sqrt(delt))/(2*a)))else:#注意根号⾥不是b²-4ac，所以根号⾥加负号print("此⽅程有两个共轭复根： {0} 和 {1}".format(complex(-b /(2*a), math.sqrt(-delt)/(2*a)),complex(-b /(2*a),-math.sqrt(-delt)/(2*a)))) 13.⽅法⼀（for循环）：n =int(input("请输⼊⾮负整数n："))while(n <0):n =int(input("请输⼊⾮负整数n："))S =1if(n ==0):print("0! = 1")if(n >0):for i in range(n,0,-1):S *= iprint(str.format("{0}! = {1}", n, S))⽅法⼆（while循环）：n =int(input("请输⼊⾮负整数n："))while(n <0):n =int(input("请输⼊⾮负整数n："))S =1if(n ==0):print("0! = 1")if(n >0):m = nwhile(m !=0):S *= mm -=1print(str.format("{0}! = {1}", n, S))14.a = random.randint(0,100)b = random.randint(0,100)S = a*bprint(str.format("整数1 = {0}，整数2 = {1}", a, b))if(a < b):a, b = b, awhile(a%b !=0):a,b = b,a%bprint("最⼤公约数 = {0}，最⼩公倍数 = {1}".format(b, S/b))满怀希望就会所向披靡。
算法设计与分析第二版课后习题及解答（可编辑）
算法设计与分析第二版课后习题及解答算法设计与分析基础课后练习答案习题1.14.设计一个计算的算法,n是任意正整数。
除了赋值和比较运算,该算法只能用到基本的四则运算操作。
算法求 //输入:一个正整数n2//输出:。
step1:a1; step2:若a*an 转step 3,否则输出a; step3:aa+1转step 2;5. a.用欧几里德算法求gcd(31415,14142)。
b. 用欧几里德算法求gcd(31415,14142),比检查min{m,n}和gcd(m,n)间连续整数的算法快多少倍?请估算一下。
a. gcd31415, 14142 gcd14142, 3131 gcd3131, 1618 gcd1618, 1513 gcd1513, 105 gcd1513, 105 gcd105, 43 gcd43, 19 gcd19, 5 gcd5, 4 gcd4, 1 gcd1, 0 1.b.有a可知计算gcd(31415,14142)欧几里德算法做了11次除法。
连续整数检测算法在14142每次迭代过程中或者做了一次除法,或者两次除法,因此这个算法做除法的次数鉴于1?14142 和 2?14142之间,所以欧几里德算法比此算法快1?14142/11 ≈1300 与2?14142/11 ≈ 2600 倍之间。
6.证明等式gcdm,ngcdn,m mod n对每一对正整数m,n都成立.Hint:根据除法的定义不难证明:如果d整除u和v, 那么d一定能整除u±v;如果d整除u,那么d也能够整除u的任何整数倍ku.对于任意一对正整数m,n,若d能整除m和n,那么d一定能整除n和rm mod nm-qn;显然,若d能整除n和r,也一定能整除mr+qn和n。
数对m,n和n,r具有相同的公约数的有限非空集,其中也包括了最大公约数。
故gcdm,ngcdn,r7.对于第一个数小于第二个数的一对数字,欧几里得算法将会如何处理?该算法在处理这种输入的过程中,上述情况最多会发生几次?Hint:对于任何形如0mn的一对数字,Euclid算法在第一次叠代时交换m和n, 即gcdm,ngcdn,m并且这种交换处理只发生一次.8.a.对于所有1≤m,n≤10的输入, Euclid算法最少要做几次除法?1次b. 对于所有1≤m,n≤10的输入, Euclid算法最多要做几次除法?5次gcd5,8习题1.21.农夫过河P?农夫W?狼 G?山羊 C?白菜2.过桥问题1,2,5,10---分别代表4个人, f?手电筒4. 对于任意实系数a,b,c, 某个算法能求方程ax^2+bx+c0的实根,写出上述算法的伪代码可以假设sqrtx是求平方根的函数算法Quadratica,b,c//求方程ax^2+bx+c0的实根的算法//输入:实系数a,b,c//输出:实根或者无解信息If a≠0D←b*b-4*a*cIf D0temp←2*ax1←-b+sqrtD/tempx2←-b-sqrtD/tempreturn x1,x2else if D0 return ?b/2*ael se return “no real roots”else //a0if b≠0 return ?c/belse //ab0if c0 return “no real numbers”else return “no real roots”5. 描述将十进制整数表达为二进制整数的标准算法a.用文字描述b.用伪代码描述解答:a.将十进制整数转换为二进制整数的算法输入:一个正整数n输出:正整数n相应的二进制数第一步:用n除以2,余数赋给Kii0,1,2,商赋给n第二步:如果n0,则到第三步,否则重复第一步第三步:将Ki按照i从高到低的顺序输出b.伪代码算法 DectoBinn//将十进制整数n转换为二进制整数的算法//输入:正整数n//输出:该正整数相应的二进制数,该数存放于数组Bin[1n]中i1while n!0 doBin[i]n%2;nintn/2;i++;while i!0 doprint Bin[i];i--;9.考虑下面这个算法,它求的是数组中大小相差最小的两个元素的差.算法略对这个算法做尽可能多的改进.算法 MinDistanceA[0..n-1]//输入:数组A[0..n-1]//输出:the smallest distance d between two of its elements 习题1.3考虑这样一个排序算法,该算法对于待排序的数组中的每一个元素,计算比它小的元素个数,然后利用这个信息,将各个元素放到有序数组的相应位置上去.a.应用该算法对列表”60,35,81,98,14,47”排序b.该算法稳定吗?c.该算法在位吗?解:a. 该算法对列表”60,35,81,98,14,47”排序的过程如下所示:b.该算法不稳定.比如对列表”2,2*”排序c.该算法不在位.额外空间for S and Count[]4.古老的七桥问题第2章习题2.17.对下列断言进行证明:如果是错误的,请举例a. 如果tn∈Ogn,则gn∈Ωtnb.α0时,Θαgn Θgn解:a这个断言是正确的。
习题答案第四章算法设计与分析吕国英
算法设计与分析（第二版）主编：吕国英习题答案第四章1.#include<stdio.h>int main(void){int buf[100];int n;int i,j,k;scanf("%d",&n);for(i=0;i<n;i++)buf[i]=2;for(i=0;i<n-1;i++){for(j=0;j<n-i-1;j++){buf[j]+=2;}}for(j=0;j<n;j++){if(buf[j]>=10){buf[j+1]+=buf[j]/10;buf[j]=buf[j]%10;}}for(i=n-1;i>=0;i--)printf("%d",buf[i]);printf("\n");return 0;}2.#include<stdio.h>int main(void){int n=2;int i;for(i=1;i<=9;i++){n=(n+2)*2;}printf("%d\n",n);return 0;}3.#include<stdio.h>int main(void){int a=54;int n;int m;printf("计算机先拿3张牌\n"); a=a-3;while(a>=0){printf("还剩%d张牌\n",a); printf("你拿几张？请输入："); scanf("%d",&n);if(n>4||n<1||n>a){printf("错误！重新拿牌\n"); continue;}a=a-n;printf("还剩%d张牌\n",a);if(a==0)break;m=5-n;printf("计算机拿%d\n",m);a=a-m;}return 0;}4.#include<stdio.h>int d;int a1,a2;int fun(int n);int main(void){int n;printf("n=?,d=?,a1=?,a2=?");scanf("%d%d%d%d\n",&n,&d,&a1,&a2); printf("%d\n",fun(n));return 0;}int fun(int n){if(n==1)return a1;if(n==2)return a2;return fun(n-2)-(fun(n-1)-d)*2;}5.#include<stdio.h>char chess[8][8];int is_safe(int row,int col);int queen(int row,int col,int n); int main(void){int i,j;for(i=0;i<8;i++)for(j=0;j<8;j++)chess[i][j]='X';queen(0,0,0);for(i=0;i<8;i++){for(j=0;j<8;j++)printf("%c ",chess[i][j]);printf("\n");}return 0;}int is_safe(int row,int col){int i,j;for(i=0;i<8;i++){if(chess[row][i]=='Q')return 0;if(chess[i][col]=='Q')return 0;}i=row;j=col;while(i!=-1&&j!=-1){if(chess[i--][j--]=='Q')return 0;}i=row;j=col;while(i!=-1&&j!=8){if(chess[i--][j++]=='Q')return 0;}i=row;j=col;while(i!=8&&j!=-1){if(chess[i++][j--]=='Q')return 0;}i=row;j=col;while(i!=8&&j!=8){if(chess[i++][j++]=='Q')return 0;}return 1;}int queen(int row,int col,int n) {int i,j;int result=0;if(n==8)return 1;elseif(is_safe(row,col)){chess[row][col]='Q';for(i=0;i<8;i++)for(j=0;j<8;j++){result+=queen(i,j,n+1);if(result>0)break;}if(result>0)return 1;else{chess[row][col]='X';return 0;}}elsereturn 0;}6.#include<stdio.h>int main(void){int i,j,k;for(i=1;i<=33;i++)for(j=1;j<=50;j++){k=100-i-j;if(k%2==0){if(3*i+2*j+k/2==100)printf("大马%d\n中马%d\n小马%d\n\n\n",i,j,k); }}return 0;}7.#include<stdio.h>int main(void){int i;for(i=1;i<=10000;i++){if(i%2==1&&i%3==2&&i%5==4&&i%6==5&&i%7==0) printf("%d\n",i);}return 0;}8.#include<stdio.h>int main(void){int i;int sum;int a1,a2,a3,a4;for(i=1000;i<=9999;i++){a1=i%10;a2=i/10%10;if(a1!=a2){a3=i/100%10;if(a1!=a3&&a2!=a3){a4=i/1000;if(a1!=a4&&a2!=a4&&a3!=a4){sum=(a1+a2+a3+a4)*(a1+a2+a3+a4);if(i%sum==0)printf("%d\n",i);}}}}return 0;}9.#include<stdio.h>#define N 10void max_min(int *a,int m,int n,int *min1,int *min2,int *max1,int *max2); int main(void){int a[N]={2,3,4,5,34,7,9,6,43,21};int min1,min2;int max1,max2;max_min(a,0,N-1,&min1,&min2,&max1,&max2);printf("min1=%d\nmin2=%d\nmax1=%d\nmax2=%d\n",min1,min2,max1,max2);return 0;}void max_min(int *a,int m,int n,int *min1,int *min2,int *max1,int *max2) {int lmin1,lmin2,lmax1,lmax2;int rmin1,rmin2,rmax1,rmax2;int mid;if(m==n){*min1=*min2=*max1=*max2=a[m];}elseif(m==n-1){if(a[m]<a[n]){*min1=a[m];*min2=a[n];*max1=a[n];*max2=a[m];}else{*min1=a[n];*min2=a[m];*max1=a[m];*max2=a[n];}}else{mid=(m+n)/2;max_min(a,m,mid,&lmin1,&lmin2,&lmax1,&lmax2); max_min(a,mid+1,n,&rmin1,&rmin2,&rmax1,&rmax2); if(lmin1<rmin1){if(lmin2<rmin1){*min1=lmin1;*min2=lmin2;}else{*min1=lmin1;*min2=rmin1;}}elseif(rmin2<lmin1)*min1=rmin1;*min2=rmin2;}else{*min1=rmin1;*min2=lmin1;}if(lmax1>rmax1){if(lmax2>rmax1){*max1=lmax1;*max2=lmax2;}else{*max1=lmax1;*max2=rmax1;}}elseif(rmax2>lmax1){*max1=rmax1;*max2=rmax2;}else{*max1=rmax1;*max2=lmax1;}}}10.#include<stdio.h>int add(int *a,int flag,int right); int main(void){int a[10]={1,2,3,4,5,6,7,8,9,10}; int sum=add(a,0,9);printf("%d\n",sum);return 0;int add(int *a,int flag,int right){int mid;if(flag==right){return a[flag];}elseif(flag==right-1){return a[flag]+a[right];}else{mid=(flag+right)/2;return add(a,flag,mid)+add(a,mid+1,right); }}11.#include<stdio.h>int main(void){int a[5][3]={{-50,17,-42},{-47,-19,-3},{36,-34,-43},{-30,-43,34},{-23,-8,-45}};int i,j;int max,n;int sum=0;for(i=0;i<5;i++){max=a[i][0];n=0;for(j=1;j<3;j++){if(a[i][j]>max){max=a[i][j];n=j;}sum+=max;printf("a[%d][%d]=%d\n",i,n,max);}printf("%d\n",sum);return 0;}12./** File: newmain.c* Author: nirnava** Created on 2010年4月22日, 下午5:21*/#include<stdio.h>#include<stdlib.h>#define N 4void matrix_mul(int *mul1,int *mul2,int *mul3,int length); void matrix_add_sub(int * A,int * B,int * C,int m,char ch); void update_half_value(int * A,int * B,int m);void get_half_value(int * A,int * B,int m);int main(void){int i,j;int mul1[N*N]={1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6};int mul2[N*N]={7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2};int mul3[N*N];matrix_mul(mul1,mul2,mul3,N);for(i=0;i<N*N;i++){printf("%5d",mul3[i]);if((i+1)%N==0)printf("\n");}return 0;}void matrix_add_sub(int * A,int * B,int * C,int m,char ch) {int i;for(i=0;i<m*m;i++){if(ch=='+')C[i]=A[i]+B[i];C[i]=A[i]-B[i];}}void update_half_value(int * A,int * B,int m) {int i,j;for(i=0;i<m/2;i++){for(j=0;j<m/2;j++){B[i*m+j]=A[i*m/2+j];}}}void get_half_value(int * A,int * B,int m) {int i,j;for(i=0;i<m/2;i++){for(j=0;j<m/2;j++){A[i*m/2+j]=B[i*m+j];}}}void matrix_mul(int *A,int *B,int *C,int m) {if(m==2){int D,E,F,G,H,I,J;D=A[0]*(B[1]-B[3]);E=A[3]*(B[2]-B[0]);F=(A[2]+A[3])*B[0];G=(A[0]+A[1])*B[3];H=(A[2]-A[0])*(B[0]+B[1]);I=(A[1]-A[3])*(B[2]+B[3]);J=(A[0]+A[3])*(B[0]+B[3]);C[0]=E+I+J-G;C[1]=D+G;C[2]=E+F;C[3]=D+H+J-F;return ;}{int A1[m*m/4],A2[m*m/4],A3[m*m/4],A4[m*m/4];int B1[m*m/4],B2[m*m/4],B3[m*m/4],B4[m*m/4];int C1[m*m/4],C2[m*m/4],C3[m*m/4],C4[m*m/4];int D[m*m/4],E[m*m/4],F[m*m/4],G[m*m/4],H[m*m/4],I[m*m/4],J[m*m/4]; int temp1[m*m/4],temp2[m*m/4];get_half_value(A1,&A[0],m);get_half_value(A2,&A[m/2],m);get_half_value(A3,&A[m*m/2],m);get_half_value(A4,&A[m*m/2+m/2],m);get_half_value(B1,&B[0],m);get_half_value(B2,&B[m/2],m);get_half_value(B3,&B[m*m/2],m);get_half_value(B4,&B[m*m/2+m/2],m);matrix_add_sub(B2,B4,temp1,m/2,'-');matrix_mul(A1,temp1,D,m/2);matrix_add_sub(B3,B1,temp1,m/2,'-');matrix_mul(A4,temp1,E,m/2);matrix_add_sub(A3,A4,temp1,m/2,'+');matrix_mul(temp1,B1,F,m/2);matrix_add_sub(A1,A2,temp1,m/2,'+');matrix_mul(temp1,B4,G,m/2);matrix_add_sub(A3,A1,temp1,m/2,'-');matrix_add_sub(B1,B2,temp2,m/2,'+');matrix_mul(temp1,temp2,H,m/2);matrix_add_sub(A2,A4,temp1,m/2,'-');matrix_add_sub(B3,B4,temp2,m/2,'+');matrix_mul(temp1,temp2,I,m/2);matrix_add_sub(A1,A4,temp1,m/2,'+');matrix_add_sub(B1,B4,temp2,m/2,'+');matrix_mul(temp1,temp2,J,m/2);matrix_add_sub(E,I,temp1,m/2,'+');matrix_add_sub(J,G,temp2,m/2,'-');matrix_add_sub(temp1,temp2,C1,m/2,'+');matrix_add_sub(D,G,C2,m/2,'+');matrix_add_sub(E,F,C3,m/2,'+');matrix_add_sub(D,H,temp1,m/2,'+');matrix_add_sub(J,F,temp2,m/2,'-');matrix_add_sub(temp1,temp2,C4,m/2,'+');update_half_value(C1,&C[0],m);update_half_value(C2,&C[m/2],m);update_half_value(C3,&C[m*m/2],m);update_half_value(C4,&C[m*m/2+m/2],m);return ;}}13.#include<stdio.h>int main(void){int a[6][7]={{16,4,3,12,6,0,3},{4,-5,6,7,0,0,2},{6,0,-1,-2,3,6,8},{5,3,4,0,0,-2,7},{-1,7,4,0,7,-5,6},{0,-1,3,4,12,4,2}};int b[6][7],c[6][7];int i,j,k;int max;int flag;int temp;for(i=0;i<6;i++)for(j=0;j<7;j++){b[i][j]=a[i][j];c[i][j]=-1;}for(i=1;i<5;i++){for(j=0;j<7;j++){max=0;for(k=j-2;k<=j+2;k++) {if(k<0)continue;elseif(k>6)break;else{if(b[i][j]+b[i-1][k]>max) {max=b[i][j]+b[i-1][k]; flag=k;}}}b[i][j]=max;c[i][j]=flag;}}for(j=1;j<=5;j++){max=0;for(k=j-2;k<=j+2;k++) {if(k<0)continue;elseif(k>6)break;else{if(b[i][j]+b[i-1][k]>max) {max=b[i][j]+b[i-1][k]; flag=k;}}}b[i][j]=max;c[i][j]=flag;}max=0;for(j=1;j<=5;j++){if(b[i][j]>max){max=b[i][j];flag=j;}}printf("%d\n",max);temp=c[i][flag];printf("%5d",a[i][temp]); for(j=i;j>0;j--){temp=c[j][temp];printf("%5d",a[j-1][temp]); }printf("\n");return 0;}14.#include<stdio.h>int main(void){int A[6]={0,3,7,9,12,13}; int B[6]={0,5,10,11,11,11}; int C[6]={0,4,6,11,12,12}; int AB[6][6];int temp[6];int abc[6];int max;int flag;int i,j,k;for(i=0;i<=5;i++){max=0;for(j=0;j<=i;j++){AB[i][j]=A[i-j]+B[j];if(AB[i][j]>max)max=AB[i][j];}temp[i]=max;}max=0;for(i=0;i<=5;i++){abc[i]=temp[i]+C[5-i];if(abc[i]>max){max=abc[i];flag=i;}}printf("max=%d\n",max); printf("c=%d\n",5-flag); max=max-C[5-flag];for(i=0;i<=flag;i++){if(AB[flag][i]==max){printf("b=%d\n",i);printf("a=%d\n",flag-i);break;}}return 0;}16.#include<stdio.h>#define N 100int search(int *a,int left,int right); int sum_buf(int *a,int left,int right); int main(void){int a[N];int i;int s;for(i=0;i<N;i++)a[i]=1;a[24]=2;s=search(a,0,N-1);printf("%d\n",s);return 0;}int sum_buf(int *a,int left,int right) {int i;int sum=0;for(i=left;i<=right;i++)sum+=a[i];return sum;}int search(int *a,int left,int right) {int mid=(left+right)/2;if(left==right-1){if(a[left]<a[right])return right;elsereturn left;}if(mid*2!=(right+left-1)){if(sum_buf(a,left,mid-1)>sum_buf(a,mid+1,right)) {return search(a,left,mid-1);}elseif(sum_buf(a,left,mid-1)<sum_buf(a,mid+1,right)) {return search(a,mid+1,right);}elsereturn mid;}else{if(sum_buf(a,left,mid)>sum_buf(a,mid+1,right)) return search(a,left,mid);elsereturn search(a,mid+1,right);}}17.#include<stdio.h>int job[6][2]={{3,8},{12,10},{5,9},{2,6},{9.3},{11,1}};int x[6],bestx[6],f1=0,bestf,f2[7]={0};void try(int i);void swap(int a,int b);int main(void){int i,j;bestf=32767;for(i=0;i<6;i++)x[i]=i;try(0);for(i=0;i<6;i++)printf("%d ",bestx[i]);printf("\nbestf=%d\n",bestf); return 0;}void try(int i){int j;if(i==6){for(j=0;j<6;j++)bestx[j]=x[j];bestf=f2[i];}else{for(j=i;j<6;j++){f1=f1+job[x[j]][0];if(f2[i]>f1)f2[i+1]=f2[i]+job[x[j]][1]; elsef2[i+1]=f1+job[x[j]][1];if(f2[i+1]<bestf){swap(i,j);try(i+1);swap(i,j);}f1=f1-job[x[j]][0];}}}void swap(int i,int j){int temp;temp=x[i];x[i]=x[j];x[j]=temp;}18.#include<stdio.h>#define N 5 //N个数字#define M 2 //M个加号char buf[N];int a[N];char b[M+1][N];int c[M+1];int try(int t);void swap(int t1,int t2); int add();void output();int min=99999;int main(){int i;for(i=0;i<N;i++){scanf("%c",&buf[i]);}a[0]=0;for(i=1;i<=M;i++){a[i]=1;}for(;i<N;i++){a[i]=0;}try(1);output();printf("%d\n",min);return 0;}int try(int t){int j;int i;int sum;if(t>=N){sum=add();if(sum<min){min=sum;for(i=0;i<M+1;i++){c[i]=atoi(b[i]);}}/*for(i=0;i<N;i++){printf("%d",a[i]);}printf("\n");*/}else{for(j=t;j<N;j++){//if(a[t]!=a[j]){swap(t,j);try(t+1);swap(t,j);}//else//try(t+1);}}}void swap(int t1,int t2) {int t;t=a[t1];a[t1]=a[t2];a[t2]=t;}int add(){int sum=0;int i=0;int j;int k=0;int h=0;for(i=0;i<M+1;i++)for(j=0;j<N;j++)b[i][j]='Q';i=0;j=0;h=0;k=0;for(j=0;j<N;j++){if(a[j]==1){h=0;i++;b[i][h]=buf[j];//printf("%d ",atoi(b[i]));//printf("%d %d %c \n",i,h,b[i][h]); h++;}else{b[i][h]=buf[j];//printf("%d %d %c \n",i,h,b[i][h]); //printf("%d ",atoi(b[i]));h++;}}/*for(i=0;i<M+1;i++){for(j=0;j<N;j++)printf("%c ",b[i][j]);printf("\n");}*/for(i=0;i<M+1;i++){sum+=atoi(b[i]);}return sum;}void output(){int i;for(i=0;i<M+1;i++){printf("%d",atoi(b[i]));if(i!=M)printf("+");}printf("=");}19.#include<stdio.h>int main(void){int buf[100];int m,n;int i,j;buf[0]=1;buf[1]=1;scanf("%d%d",&n,&m);for(i=1;i<n;i++){buf[i+1]=buf[i];for(j=i;j>0;j--){buf[j]=buf[j]+buf[j-1];}}printf("%d\n",buf[m]);return 0;}20.#include<stdio.h>int max_sum4(int *a,int n);int max_sub_sum(int *a,int left,int right);int main(void){int a[6]={-2,11,-4,13,-5,-2};printf("%d\n",max_sum4(a,5));return 0;}int max_sum4(int *a,int n){return max_sub_sum(a,0,n);}int max_sub_sum(int *a,int left,int right){int center,i,max,left_sum,right_sum,s1,s2,s3,s4,lefts,rights,leftl,rightl; int buf[4];if(left==right)return a[left];else{center=(left+right)/2;left_sum=max_sub_sum(a,left,center); right_sum=max_sub_sum(a,center+1,right); s1=0;lefts=0;for(i=center;i>=left;i--){lefts+=a[i];if(lefts>s1)s1=lefts;}s2=0;rights=0;for(i=center+1;i<=right;i++){rights+=a[i];if(rights>s2)s2=rights;}s3=0;leftl=0;for(i=left;i<=center;i++){leftl+=a[i];if(leftl>s3)s3=leftl;}s4=0;rightl=0;for(i=right;i>=center+1;i--){rightl+=a[i];if(rightl>s4)s4=rightl;}buf[0]=s1+s2;buf[1]=s4+s3;buf[2]=left_sum;buf[3]=right_sum;max=0;for(i=0;i<=3;i++){if(buf[i]>max)max=buf[i];}return max; }}。
算法分析与设计第二版习题答案-第三章到第五章
算法设计与分析（第二版）习题答案主编：吕国英算法设计与分析（第二版）习题答案（第三章）第三章：1.#include<stdlib.h>#include<stdio.h>int main(int argc,char **argv){int n;int i,j,k;int *buf;printf("请输入n的数值:");scanf("%d",&n);buf=(int *)malloc(n*sizeof(int));for(i=0;i<n;i++){buf[i]=2;}for(i=n-2;i>=0;i--){for(j=i;j>=0;j--){buf[j]+=2;}}for(k=0;k<=n-2;k++){if(buf[k]>=10){buf[k+1]+=buf[k]/10;buf[k]%=10;}}for(i=n-1;i>=0;i--)printf("%d",buf[i]);printf("\n");return 0;}2.#include<stdio.h>int main(int argc,char **argv){int buf[6][6];int i,j;printf("任意输入6个数字:");for(i=0;i<6;i++) scanf("%d",&buf[0][i]);for(i=0;i<5;i++){ for(j=0;j<5;j++) { buf[i+1][j+1]=buf[i][j]; } buf[i+1][0]=buf[i][j];}for(i=0;i<6;i++){ for(j=0;j<6;j++) printf("%d ",buf[i][j]); printf("\n");}return 0;}3.#include<stdio.h>#define N 7int main(int argc,char **argv){int buf[N][N];int i,j,k,m,n;int a=0,b=N-1;intcount=1;for(i=0;i<(N/2)+(N%2);i++){ for(j=a;j<=b;j++) { buf[a][j]=count++; } f or(k=a+1;k<=b;k++) { buf[k][b]=count++; } for(m=b-1;m>=a;m--) { buf[b][m]=count++; } for(n=b-1;n>a;n--) { buf[n][a]=count++; } a++; b--;}for(i=0;i<N;i++){ for(j=0;j<N;j++) printf("]",buf[i][j]); printf("\n");}return 0;}4.#include<stdio.h>#define N 5int main(int argc,char **argv){int buf[N][N];inti,j,k;int count=1;int n=0;for(i=0;i<N;i++){ for(k=0,j=n;j>=0;j--,k++) buf[j][k]=count++; n++;}for(i=0;i<N;i++){ for(j=0;j<N-i;j++) printf("]",buf[i][j]); printf("\n");}return 0;}5.#include<stdio.h>#define N 5int main(int argc,char **argv){int buf[N][N];int i,j;int a=0,b=N-1;intcount=1;for(i=0;i<N/2+N%2;i++){ for(j=a;j<=b;j++) buf[a][j]=count; for(j=a+1;j<= b;j++) buf[j][b]=count; for(j=b-1;j>=a;j--) buf[b][j]=count; for(j=b-1;j>a;j--) buf[j][a]=count; count++; a++; b--;}for(i=0;i<N;i++){ for(j=0;j<N;j++) printf("]",buf[i][j]); printf("\n");}return 0;}6.#include<stdio.h>#include<stdlib.h>typedef struct s_node s_list;typedef s_list*link;struct s_node{char ch;int flag;link next;};link top;void push(char ch,int flag){link newnode;newnode=(link)malloc(sizeof(s_list));newnode->ch=ch;newnode->flag=flag;newnode->next=NULL;if(top==NULL) { top=newnode; }else { newnode->next=top; top=newnode; }}int pop(){int flag;linkstack;if(top!=NULL) { stack=top; top=top->next; flag=stack->flag; free(stack); }return flag;}int op(char ch){switch(ch) { case '+': return 1; break; case '-': return 2; break; case '*': return 3; break; case'/': return 4; break; default: return 5; }}void nirnava(char *buf,intcount)//count个数，buf数组{int bool=1;int min;int j;int i;int k;int flag;for(i=0;i<count;i++){if(buf[i]=='(')push(buf[i],i);if(buf[i]==')'){flag=pop();if(flag!=0){if((buf[flag-1]=='(')&&(buf[i+1]==')')){buf[flag]='!';buf[i]='!';}}min=op(buf[flag]);for(j=flag+1;j<i;j++){if(buf[j]=='('){push(buf[j],j);bool=0;continue;}elseif(buf[j]==')'){pop();bool=1;continue;}if(bool==1){if(min>op(buf[j]))min=op(buf[j]);}}if(i<count-1){if((buf[i+1]=='+')||(buf[i+1]=='-')){if(flag==0){buf[i]='!';buf[flag]='!';}elseif(op(buf[flag-1])<=min){buf[i]='!';buf[flag]='!';}}elseif((buf[i+1]=='*')||(buf[i+1]=='/')){if(flag==0){buf[i]='!';buf[flag]='!';}elseif((min>=op(buf[i+1])&&op(buf[flag-1])<=min)) {buf[i]='!';buf[flag]='!';}}}elseif(i==count-1){if(flag==0){buf[i]='!';buf[flag]='!';}elseif(op(buf[flag-1])<=min){buf[i]='!';buf[flag]='!';}}}}for(k=0;k<count;k++){if(buf[k]!='!')printf("%c",buf[k]);}printf("\n");}int main(void){char buf[255];int i;for(i=0;i<255;i++){scanf("%c",&buf[i]);if(buf[i]=='\n')break;}buf[i]='\0';nirnava(buf,i);return 0;}7.#include<stdio.h>#include<stdlib.h>int ack(int m,int n);int count=0;int main(int argc,char **argv){intm,n;scanf("%d%d",&m,&n);printf("%d\n",ack(m,n));printf("%d\n",count);return 0;}int ack(int m,int n){count++;if(m==0) return n+1;else if(n==0) return ack(m-1,1); else return ack(m-1,ack(m,n-1));}8.#include<stdio.h>char buf[1024];intis_huiwen(int a,int count){if(a==count/2) { return1; }else if(buf[a]==buf[count-a-1]) return (is_huiwen(a-1,count))&&1; else {return 0; }}int main(void){int count;inti;for(i=0;i<1024;i++) { scanf("%c",&buf[i]); if(buf[i]=='\n')break; }count=i;i--;printf("%d",is_huiwen(i,count));return 0;}9.#include<stdio.h>char buf[100];int pos(int a,int b){if(b-a==1) return 1;else if(b-a==0) return 1; else return pos(a,b-1)+pos(a,b-2);}int main(void){inta,b;scanf("%d%d",&a,&b);printf("%d",pos(a,b));return 0;}10.#include<stdio.h>#define MAX 1024int buf[MAX];int main(void){int m,n;inti;scanf("%d%d",&m,&n);for(i=0;i<MAX;i++) buf[i]=0;i=0;while(buf[i%m]==0) { buf[i%m]=1; i+=n; }for(i=0;i<m;i++) { if(buf[i]==0)printf("%d",i); }return 0;}11.#include<stdio.h>int main(void){int temp,temp1;int count=0;int n;inti;scanf("%d",&n);for(i=1;i<=n;i++) { temp=i; if(temp==5)count++; elseif(te mp==0) { temp1=i; while((temp1)==0) { temp1=temp1/10; count++; } } }printf("%d",count);return 0;}12.#include<stdio.h>int main(void){int count=0;int buf[53];inti,n;for(i=1;i<53;i++) { buf[i]=1; }for(n=2;;n++) { for(i=n;i<53;i+=n){ buf[i ]=1-buf[i]; count++; if(count>=104) break;} if(count>=104)break; }for(i=1;i<53;i ++) { if(buf[i]==1)printf("%d ",i); }printf("\n");return 0;}13.#include<stdio.h>int main(void){inta,b,c,d,e;for(a=1;a<=5;a++) for(b=1;b<=5;b++) if(a!=b)for(c=1;c<=5;c++) if(c!=a &&c!=b) for(d=1;d<=5;d++) if(d!=a&&d!=b&&d!=c) { e=15-a-b-c-d; if(e!=a&&e!=b&&e!=c&&e!=d) if(((b==3)+(c==5)==1)&&((d==2)+(e==4)==1 )&&((b==1)+(e==4)==1)&&((c==1)+(b==2)==1)&&((d==2)+(a==3)==1)) printf(" a=%d,b=%d,c=%d,d=%d,e=%d",a,b,c,d,e); }return 0;}14.#include<stdio.h>int main(void){int buf[3];int i;int mul;inttemp;for(i=10;i<=31;i++) { mul=i*i; temp=mul; buf[0]=temp; temp=temp /10; buf[1]=temp; temp=temp/10; buf[2]=temp; if((buf[0]==buf[1])||(buf[0] ==buf[2])||(buf[1]==buf[2])){ printf("%d^2=%d\n",i,mul);} }return0;}15.#include<stdio.h>int main(void){inta,b,c;for(a=1;a<=3;a++) for(b=1;b<=3;b++) if(a!=b){ c=6-a-b; if(c!=a&&c!=b) if((a!=1)&&((c!=1)&&(c!=3))==1) printf("a=%d,b=%d,c=% d",a,b,c);}return 0;}16.#include<stdio.h>int main(void){int k;intn;scanf("%d",&n);k=(n%4==0)+(n%7==0)*2+(n%9==0)*4;switch(k) { case7: printf("all"); break; case 6: printf("7 and 9"); break; case5: printf("4 and 9"); break; case 4: printf("9"); break; case 3: printf("4 and 7"); break; case 2: printf("7"); break; case1: printf("4"); break; case 0: printf("none"); break; }return0;}17.#include<stdio.h>int main(void){int a,b,c,d;printf("please think of a number between 1 and 100.\n");printf("your number divided by 3 has a remainder of");scanf("%d",&a);printf("your number divided by 4 has a remainder of");scanf("%d",&b);printf("your number divided by 7 has a remainder of");scanf("%d",&c);printf("let me think amoment...\n");d=36*c+28*a+21*b;while(d>84) d=d-84;printf("your numberwas %d\n",d);return 0;}18.#include<stdio.h>int main(void){int buf[10];int i,j;int mul;int temp1,temp2;intbool;for(i=5000;i<=9999;i++) { bool=0; for(j=0;j<10;j++)buf[j]=0; temp1=i; while(temp1>0){ if((++buf[temp1])>1) { bool=1; break; } temp1/=10; } if(bool==1)continue; mul=i*2; temp2=mul; while(temp2>0){ if((++buf[t emp2])>1) { bool=1; break; } temp2/=10;} if(bool==1)continue; pri ntf("2*%d=%d\n",i,mul); }return 0;}19.#include<stdio.h>#include<stdlib.h>int ppow(int a,int b){int mul=1;int i;for(i=0;i<b;i++) { mul=a*mul; }return mul;}int main(void){int t;char buf[10];int i,j,k;intsum=0;for(i=0;i<10;i++) { scanf("%c",&buf[i]); if(buf[i]=='\n')break; }buf[i]= '\0';for(j=0;j<i;j++) { if((buf[j]>='0')&&(buf[j]<='9'))buf[j]=buf[j]-48; elseif((buf[j]>='A')&&(buf[j]<='F')) buf[j]=buf[j]-55;else exit(1); }k=0;for(j=i-1;j>=0;j--) { t=ppow(16,k); sum=sum+t*(int)buf[j]; k++; }printf("%d\n",sum);return 0;}20.#include<stdio.h>int main(void){int a;int b;int c;int i;intbuf[10];for(a=10;a<=99;a++) { for(i=0;i<10;i++)buf[i]=0; if((++buf[a]>1)||(++b uf[a/10]>1))continue; for(b=100;b<=999;b++){ for(i=0;i<10;i++) { if((i!=a)& &i!=a/10) buf[i]=0; } if((++buf[b]>1)||(++buf[b/10]>1)||(++buf[b/100]>1)) conti nue; c=a*b; if(c<10000&&c>999) { if((++buf[c]>1)||(++buf[c/10]>1)||(++buf[c /100]>1)||(++buf[c/1000]>1)) continue; else printf("%d*%d=%d\n",a,b,c); }} }return 0;}21.#include<stdio.h>int main(void){int a;int b;int i;int t;int buf[10];int bool;for(a=317;a<1000;a++) { bool=0; for(i=0;i<10;i++)buf[i]=0; if((++buf[ a]>1)||(++buf[a/10]>1)||(++buf[a/100]>1))continue; b=a*a; t=b; for(i=0;i<6;i++ ){ if(++buf[t]>1) { bool=1; break; } t=t/10;} if(bool==1)continue; p rintf("%d^2=%d\n",a,b); }return 0;}22.#include<stdio.h>int main(void){intbuf[100];int i;int n;int max;inttemp;for(i=1;i<100;i++) { scanf("%d",&buf[i]); if(buf[i]==0)break; }n=i;max =buf[1]+buf[2]+buf[3]+buf[4];for(i=2;i!=1;i++) { temp=buf[i]+buf[(i+1)]+buf[(i+2 )]+buf[(i+3)]; if(temp>max)max=temp; }printf("max=%d\n",max);return0;}23.#include<stdio.h>void nirnava(int n){if(n<10) printf("%d",n);else { nirnava(n/10); printf("%d ",n); }}int main(void){int count=0;int n;int i;int t;scanf("%d",&n);t=n;while(t>0) { printf("%d",t); t=t/10; count++; }printf("\n");nirnava(n);printf("\n%d位数\n",count);}24.#include<stdio.h>int main(void){int buf[4]={2,3,5,7};int i,j,k,temp,m;int bool;int mul;for(i=0;i<4;i++)for(j=0;j<4;j++)for(k=0;k<4;k++)for(m=0;m<4;m++){bool=0;mul=(buf[i]+buf[j]*10+buf[k]*100)*buf[m];if(mul<1000)continue;temp=mul;while(temp>0){if((temp==2)||(temp==3)||(temp==5)||(temp==7)){}else{bool=1;break;}temp/=10;}if(bool==0){printf("%d%d%d * %d = %d\n",buf[k],buf[j],buf[i],buf[m],mul); }}return 0;}25.#include<stdio.h>int main(void){int buf[4]={2,3,5,7};int i,j,k,m,n;int bool;int mul,mul1,mul2;int temp,temp1,temp2;for(i=0;i<4;i++)for(j=0;j<4;j++)for(k=0;k<4;k++)for(m=0;m<4;m++)for(n=0;n<4;n++){bool=0;mul=(buf[i]+buf[j]*10+buf[k]*100)*(buf[m]+buf[n]*10);mul1=(buf[i]+buf[j]*10+buf[k]*100)*buf[m];mul2=(mul-mul1)/10;if((mul<10000)||(mul1<1000)||(mul2<1000))continue;temp=mul;temp1=mul1;temp2=mul2;while(temp>0){if((temp==2)||(temp==3)||(temp==5)||(temp==7)){}else{bool=1;break;}temp/=10;}if(bool==0){while(temp1>0){if((temp1==2)||(temp1==3)||(temp1==5)||(temp1==7)){}else{bool=1;break;}temp1/=10;}}if(bool==0)while(temp2>0){if((temp2==2)||(temp2==3)||(temp2==5)||(temp2==7)){}else{bool=1;break;}temp2/=10;}if(bool==0){printf("第一行: %d%d%d\n第二行: %d%d\n第三行: %d\n第四行: %d\n第五行: %d\n\n\n\n\n",buf[i],buf[j],buf[k],buf[m],buf[n],mul1,mul2,mul);}}return 0;}26.#include<stdio.h>//从a到b是不是循环节int is_xunhuan(int *buf,int a,int b) {int i;if(a==b){for(i=1;i<10;i++){if(buf[a]==buf[a+i]){}elsereturn 0;}}elsefor(i=a;i<=b;i++){if(buf[i]==buf[i+b-a+1]){}else{return 0;}}return 1;}int main(void){int buf[1024];int yushu;int m,n;int i,j,k;scanf("%d%d",&m,&n);yushu=m;buf[0]=0;i=1;while(yushu!=0){yushu=yushu*10;buf[i]=yushu/n;yushu=yushu%n;i++;if(i==1024)break;}if(i<1024){printf("有限小数\n");printf("%d.",buf[0]);for(j=1;j<i;j++)printf("%d",buf[j]);printf("\n");}else{printf("循环小数\n");for(i=1;i<100;i++)for(j=i;j<200;j++){if(is_xunhuan(buf,i,j)){printf("%d.",buf[0]);if(i>1){for(k=1;k<i;k++)printf("%d",buf[k]);}printf("(");for(k=i;k<=j;k++)printf("%d",buf[k]);printf(")");printf("\n");return 0;}}}return 0;}27.#include<stdio.h>int main(void){int n;char eng[12][10]={"一月","二月","三月","四月","五月","六月","七月","八月","九月","十月","十一月","十二月"};scanf("%d",&n);printf("%s\n",eng[n-1]);return 0;}第四章1.#include<stdio.h>int main(void){int buf[100];int n;int i,j,k;scanf("%d",&n);for(i=0;i<n;i++)buf[i]=2;for(i=0;i<n-1;i++){for(j=0;j<n-i-1;j++) {buf[j]+=2;}}for(j=0;j<n;j++){if(buf[j]>=10) {buf[j+1]+=buf[j]/10; buf[j]=buf[j];}}for(i=n-1;i>=0;i--)printf("%d",buf[i]); printf("\n");return 0;}2.#include<stdio.h>int main(void){int n=2;int i;for(i=1;i<=9;i++){n=(n+2)*2;}printf("%d\n",n);return 0;}3.#include<stdio.h>int main(void){int a=54;int n;int m;printf("计算机先拿3张牌\n");a=a-3;while(a>=0){printf("还剩%d张牌\n",a);printf("你拿几张？请输入：");scanf("%d",&n);if(n>4||n<1||n>a){printf("错误！重新拿牌\n");continue;}a=a-n;printf("还剩%d张牌\n",a);if(a==0)break;m=5-n;printf("计算机拿%d\n",m);a=a-m;}return 0;}4.#include<stdio.h>int d;int a1,a2;int fun(int n);int main(void){int n;printf("n=?,d=?,a1=?,a2=?");scanf("%d%d%d%d\n",&n,&d,&a1,&a2); printf("%d\n",fun(n));return 0;}int fun(int n){if(n==1)return a1;if(n==2)return a2;return fun(n-2)-(fun(n-1)-d)*2;}5.#include<stdio.h>char chess[8][8];int is_safe(int row,int col);int queen(int row,int col,int n);int main(void){int i,j;for(i=0;i<8;i++)for(j=0;j<8;j++)chess[i][j]='X';queen(0,0,0);for(i=0;i<8;i++){for(j=0;j<8;j++)printf("%c ",chess[i][j]);printf("\n");}return 0;}int is_safe(int row,int col){int i,j;for(i=0;i<8;i++) { if(chess[row][i]=='Q')return 0; if(chess[i][col]=='Q')return 0; }i=row;j=col;while(i!=-1&&j!=-1) { if(chess[i--][j--]=='Q')return 0; }i=row;j=col;while(i!=-1&&j!=8) { if(chess[i--][j++]=='Q')return 0; }i=row;j=col;while(i!=8&&j!=-1) { if(chess[i++][j--]=='Q')return0; }i=row;j=col;while(i!=8&&j!=8) { if(chess[i++][j++]=='Q')return 0; }return 1;}int queen(int row,int col,int n){int i,j;int result=0;if(n==8) return1;else if(is_safe(row,col)) {chess[row][col]='Q';for(i=0;i<8;i++) for(j=0;j<8;j++) { result+=queen(i,j,n+1); if(result>0) break; }if(result>0) return1;else { chess[row][col]='X'; return 0; } } else return0;}6.#include<stdio.h>int main(void){inti,j,k;for(i=1;i<=33;i++) for(j=1;j<=50;j++) {k=100-i-j;if(k%2==0) { if(3*i+2*j+k/2==100) printf("大马%d\n中马%d\n小马%d\n\n\n",i,j,k);}}return 0;}7.#include<stdio.h>int main(void){int i;for(i=1;i<=10000;i++){if(i%2==1&&i%3==2&&i%5==4&&i%6==5&&i%7==0) printf("%d\n",i);}return 0;}8.#include<stdio.h>int main(void){int i;int sum;int a1,a2,a3,a4;for(i=1000;i<=9999;i++){a1=i;a2=i/10;if(a1!=a2){a3=i/100;if(a1!=a3&&a2!=a3){a4=i/1000;if(a1!=a4&&a2!=a4&&a3!=a4){sum=(a1+a2+a3+a4)*(a1+a2+a3+a4);if(i%sum==0)printf("%d\n",i);}}}}return 0;}9.#include<stdio.h>#define N 10void max_min(int *a,int m,int n,int *min1,int *min2,int *max1,int *max2);int main(void){int a[N]={2,3,4,5,34,7,9,6,43,21};int min1,min2;int max1,max2;max_min(a,0,N-1,&min1,&min2,&max1,&max2);printf("min1=%d\nmin2=%d\nmax1=%d\nmax2=%d\n",min1,min2,max1,max2); return 0;}void max_min(int *a,int m,int n,int *min1,int *min2,int *max1,int *max2){int lmin1,lmin2,lmax1,lmax2;int rmin1,rmin2,rmax1,rmax2;int mid;if(m==n){*min1=*min2=*max1=*max2=a[m];}elseif(m==n-1){if(a[m]<a[n]){*min1=a[m];*min2=a[n];*max1=a[n];*max2=a[m];}else{*min1=a[n];*min2=a[m];*max1=a[m];*max2=a[n];}}else{mid=(m+n)/2;max_min(a,m,mid,&lmin1,&lmin2,&lmax1,&lmax2);max_min(a,mid+1,n,&rmin1,&rmin2,&rmax1,&rmax2);if(lmin1<rmin1){if(lmin2<rmin1){*min1=lmin1;*min2=lmin2;}else{*min1=lmin1;*min2=rmin1;}}elseif(rmin2<lmin1) {*min1=rmin1; *min2=rmin2; }else{*min1=rmin1; *min2=lmin1; }if(lmax1>rmax1){if(lmax2>rmax1) {*max1=lmax1;*max2=lmax2;}else{*max1=lmax1;*max2=rmax1;}}elseif(rmax2>lmax1) {*max1=rmax1; *max2=rmax2; }else{*max1=rmax1; *max2=lmax1; }}}10.#include<stdio.h>int add(int *a,int flag,int right);int main(void){int a[10]={1,2,3,4,5,6,7,8,9,10};int sum=add(a,0,9);printf("%d\n",sum);return 0;}int add(int *a,int flag,int right){int mid;if(flag==right){return a[flag];}elseif(flag==right-1){return a[flag]+a[right];}else{mid=(flag+right)/2;return add(a,flag,mid)+add(a,mid+1,right); }}11.#include<stdio.h>int main(void){int a[5][3]={{-50,17,-42},{-47,-19,-3},{36,-34,-43},{-30,-43,34},{-23,-8,-45}};int i,j;int max,n;int sum=0;for(i=0;i<5;i++){max=a[i][0];n=0;for(j=1;j<3;j++){if(a[i][j]>max){max=a[i][j];n=j;}}sum+=max;printf("a[%d][%d]=%d\n",i,n,max);}printf("%d\n",sum);return 0;}12.#include<stdio.h>#include<stdlib.h>#define N 4void matrix_mul(int *mul1,int*mul2,int *mul3,int length);void matrix_add_sub(int * A,int * B,int * C,int m,char ch);void update_half_value(int * A,int * B,int m);void get_half_value(int * A,int * B,int m);int main(void){int i,j;int mul1[N*N]={1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6};intmul2[N*N]={7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2};intmul3[N*N];matrix_mul(mul1,mul2,mul3,N);for(i=0;i<N*N;i++) { printf("]",mul3[ i]); if((i+1)%N==0) printf("\n"); }return 0;}void matrix_add_sub(int * A,int * B,int * C,int m,char ch){ inti; for(i=0;i<m*m;i++) { if(ch=='+') C[i]=A[i]+B[i]; else C[i]= A[i]-B[i]; }}void update_half_value(int * A,int * B,int m){ inti,j; for(i=0;i<m/2;i++) { for(j=0;j<m/2;j++) { B[i*m+j]=A[i*m/2+j]; } }}void get_half_value(int * A,int * B,int m){ inti,j; for(i=0;i<m/2;i++) { for(j=0;j<m/2;j++) { A[i*m/2+j]=B[i*m+j]; } }}void matrix_mul(int *A,int *B,int *C,int m){if(m==2) { intD,E,F,G,H,I,J; D=A[0]*(B[1]-B[3]); E=A[3]*(B[2]-B[0]); F=(A[2]+A[3])*B[0]; G=(A[0]+A[1])*B[3]; H=(A[2]-A[0])*(B[0]+B[1]); I=(A[1]-A[3])*(B[2]+B[3]); J=(A[0]+A[3])*(B[0]+B[3]); C[0]=E+I+J-G; C[1]=D+G; C[2]=E+F; C[3]=D+H+J-F; return ; }else { intA1[m*m/4],A2[m*m/4],A3[m*m/4],A4[m*m/4]; intB1[m*m/4],B2[m*m/4],B3[m*m/4],B4[m*m/4]; intC1[m*m/4],C2[m*m/4],C3[m*m/4],C4[m*m/4]; intD[m*m/4],E[m*m/4],F[m*m/4],G[m*m/4],H[m*m/4],I[m*m/4],J[m*m/4]; int temp1[m*m/4],temp2[m*m/4]; get_half_value(A1,&A[0],m); get_half_value(A2, &A[m/2],m); get_half_value(A3,&A[m*m/2],m); get_half_value(A4,&A[m*m/2 +m/2],m); get_half_value(B1,&B[0],m); get_half_value(B2,&B[m/2],m); get_ half_value(B3,&B[m*m/2],m); get_half_value(B4,&B[m*m/2+m/2],m); matrix_a dd_sub(B2,B4,temp1,m/2,'-'); matrix_mul(A1,temp1,D,m/2); matrix_add_sub(B3,B1,temp1,m/2,'-'); matrix_mul(A4,temp1,E,m/2); matrix_add_sub(A3,A4,temp1,m/2,'+'); matri x_mul(temp1,B1,F,m/2); matrix_add_sub(A1,A2,temp1,m/2,'+'); matrix_mul(temp1,B4,G,m/2); matrix_add_sub(A3,A1,temp1,m/2,'-'); matrix_add_sub(B1,B2,temp2,m/2,'+'); matrix_mul(temp1,temp2,H,m/2); m atrix_add_sub(A2,A4,temp1,m/2,'-'); matrix_add_sub(B3,B4,temp2,m/2,'+'); matrix_mul(temp1,temp2,I,m/2); ma trix_add_sub(A1,A4,temp1,m/2,'+'); matrix_add_sub(B1,B4,temp2,m/2,'+'); matri x_mul(temp1,temp2,J,m/2); matrix_add_sub(E,I,temp1,m/2,'+'); matrix_add_sub(J ,G,temp2,m/2,'-'); matrix_add_sub(temp1,temp2,C1,m/2,'+'); matrix_add_sub(D,G,C2,m/2,'+'); matrix_add_sub(E,F,C3,m/2,'+'); matrix_add_sub(D,H,temp1,m/2,'+'); matrix_add _sub(J,F,temp2,m/2,'-'); matrix_add_sub(temp1,temp2,C4,m/2,'+'); update_half_value(C1,&C[0],m); update_half_value(C2,&C[m/2],m); update_half_value(C3,&C[m*m/2],m); updat e_half_value(C4,&C[m*m/2+m/2],m); return ; }}13.#include<stdio.h>intmain(void){int a[6][7]={ {16,4,3,12,6,0,3}, {4,-5,6,7,0,0,2}, {6,0,-1,-2,3,6,8}, {5,3,4,0,0,-2,7}, {-1,7,4,0,7,-5,6}, {0,-1,3,4,12,4,2}};intb[6][7],c[6][7];int i,j,k;int max;int flag;inttemp;for(i=0;i<6;i++) for(j=0;j<7;j++) {b[i][j]=a[i][j];c[i][j]=-1; }for(i=1;i<5;i++) { for(j=0;j<7;j++){ max=0; for(k=j-2;k<=j+2;k++) { if(k<0) continue; else if(k>6) break; else { if(b[i][j ]+b[i-1][k]>max) { max=b[i][j]+b[i-1][k]; flag=k; } } } b[i][j]=max; c[i][j]=flag;} }for(j=1;j<=5;j++) { max=0; for(k=j-2;k<=j+2;k++){ if(k<0) continue; else if(k>6) break; else { if(b[i][j]+ b[i-1][k]>max) { max=b[i][j]+b[i-1][k]; flag=k; } }} b[i][j]=max; c[i][j]=flag; }max=0;for(j=1;j<=5;j++) { if(b[i][j]>max){ max=b[i][j]; flag=j;} }printf("%d\n",max);temp=c[i][flag];pri ntf("]",a[i][temp]);for(j=i;j>0;j--) { temp=c[j][temp]; printf("]",a[j-1][temp]); }printf("\n");return 0;}14.#include<stdio.h>int main(void){intA[6]={0,3,7,9,12,13};int B[6]={0,5,10,11,11,11};int C[6]={0,4,6,11,12,12};intAB[6][6];int temp[6];int abc[6];int max;int flag;inti,j,k;for(i=0;i<=5;i++) { max=0; for(j=0;j<=i;j++){ AB[i][j]=A[i-j]+B[j]; if(AB[i][j]>max) max=AB[i][j];} temp[i]=max; }max=0;for(i=0;i<=5;i ++) { abc[i]=temp[i]+C[5-i]; if(abc[i]>max){ max=abc[i]; flag=i;} }printf("max=%d\n",max);printf("c=%d \n",5-flag);max=max-C[5-flag];for(i=0;i<=flag;i++) { if(AB[flag][i]==max){ printf("b=%d\n",i); printf("a= %d\n",flag-i); break;} }return 0;}16.#include<stdio.h>#define N 100int search(int*a,int left,int right);int sum_buf(int *a,int left,int right);int main(void){int a[N];int i;int s;for(i=0;i<N;i++) a[i]=1;a[24]=2;s=search(a,0,N-1);printf("%d\n",s);return 0;}int sum_buf(int *a,int left,int right){int i;intsum=0;for(i=left;i<=right;i++) sum+=a[i];return sum;}int search(int *a,int left,int right){int mid=(left+right)/2;if(left==right-1) { if(a[left]<a[right])returnright; elsereturn left; }if(mid*2!=(right+left-1)) { if(sum_buf(a,left,mid-1)>sum_buf(a,mid+1,right)){ return search(a,left,mid-1);} elseif(sum_buf(a,left,mid-1)<sum_buf(a,mid+1,right)) { returnsearch(a,mid+1,right); }else returnmid; }else { if(sum_buf(a,left,mid)>sum_buf(a,mid+1,right))returnsearch(a,left,mid); elsereturn search(a,mid+1,right); }}17.#include<stdio.h>int job[6][2]={{3,8},{12,10},{5,9},{2,6},{9.3},{11,1}};intx[6],bestx[6],f1=0,bestf,f2[7]={0};void try(int i);void swap(int a,int b);intmain(void){inti,j;bestf=32767;for(i=0;i<6;i++) x[i]=i;try(0);for(i=0;i<6;i++) printf("%d",bestx[i]);printf("\nbestf=%d\n",bestf);return 0;}void try(int i){intj;if(i==6) { for(j=0;j<6;j++)bestx[j]=x[j]; bestf=f2[i]; }else { for(j=i;j<6;j ++){ f1=f1+job[x[j]][0]; if(f2[i]>f1) f2[i+1]=f2[i]+job[x[j]][1]; else f2[i+1]=f1 +job[x[j]][1]; if(f2[i+1]<bestf) { swap(i,j); try(i+1); swap(i,j); } f1=f1 -job[x[j]][0];} }}void swap(int i,int j){inttemp;temp=x[i];x[i]=x[j];x[j]=temp;}18.#include<stdio.h>#define N 5 //N个数字#define M 2 //M个加号char buf[N];int a[N];char b[M+1][N];int c[M+1];int try(int t);void swap(int t1,int t2);int add();void output();int min=99999;int main(){int i;for(i=0;i<N;i++){scanf("%c",&buf[i]);}a[0]=0;for(i=1;i<=M;i++){a[i]=1;}for(;i<N;i++){a[i]=0;}try(1);output();printf("%d\n",min);return 0;}int try(int t){int j;int i;int sum;if(t>=N){sum=add();if(sum<min){min=sum;for(i=0;i<M+1;i++) {c[i]=atoi(b[i]);}}}else{for(j=t;j<N;j++) {//if(a[t]!=a[j]){swap(t,j);try(t+1);swap(t,j);}//else//try(t+1);}}}void swap(int t1,int t2) {int t;t=a[t1];a[t1]=a[t2];a[t2]=t;}int add(){int sum=0;int i=0;int j;int k=0;int h=0;for(i=0;i<M+1;i++)for(j=0;j<N;j++)b[i][j]='Q';i=0;j=0;h=0;k=0;for(j=0;j<N;j++){if(a[j]==1){h=0;i++;b[i][h]=buf[j];//printf("%d ",atoi(b[i]));//printf("%d %d %c \n",i,h,b[i][h]);h++;}else{b[i][h]=buf[j];//printf("%d %d %c \n",i,h,b[i][h]);//printf("%d ",atoi(b[i]));h++;}}for(i=0;i<M+1;i++){sum+=atoi(b[i]);}return sum;}void output(){int i;for(i=0;i<M+1;i++){printf("%d",atoi(b[i]));if(i!=M)printf("+");}printf("=");}19.#include<stdio.h>int main(void){int buf[100];int m,n;inti,j;buf[0]=1;buf[1]=1;scanf("%d%d",&n,&m);for(i=1;i<n;i++) { buf[i+1]=buf[i];。
算法分析与设计作业及参考答案
算法分析与设计作业及参考答案作业题目1、请分析冒泡排序算法的时间复杂度和空间复杂度，并举例说明其在实际中的应用场景。
2、设计一个算法，用于在一个未排序的整数数组中找到第二大的元素，并分析其时间复杂度。
3、比较贪心算法和动态规划算法的异同，并分别举例说明它们在解决问题中的应用。
参考答案1、冒泡排序算法时间复杂度：冒泡排序的基本思想是通过相邻元素的比较和交换，将最大的元素逐步“浮”到数组的末尾。
在最坏情况下，数组完全逆序，需要进行 n 1 轮比较和交换，每一轮比较 n i 次（i 表示当前轮数），所以总的比较次数为 n(n 1) ／ 2，时间复杂度为 O(n^2)。
在最好情况下，数组已经有序，只需要进行一轮比较，时间复杂度为 O(n)。
平均情况下，时间复杂度也为 O(n^2)。
空间复杂度：冒泡排序只在原数组上进行操作，不需要额外的存储空间，空间复杂度为 O(1)。
应用场景：冒泡排序算法简单易懂，对于规模较小的数组，或者对算法的简单性要求较高而对性能要求不是特别苛刻的场景，如对少量数据进行简单排序时，可以使用冒泡排序。
例如，在一个小型的学生成绩管理系统中，需要对一个班级的少量学生成绩进行排序展示，冒泡排序就可以满足需求。
2、找到第二大元素的算法以下是一种使用遍历的方法来找到未排序整数数组中第二大元素的算法：｀｀｀pythondef find_second_largest(arr)：largest ＝ arr0second_largest ＝ float(＇inf'）for num in arr:if num ＞ largest:second_largest ＝ largestlargest ＝ numelif num ＞ second_largest and num!＝ largest:second_largest ＝ numreturn second_largest｀｀｀时间复杂度分析：这个算法需要遍历数组一次，所以时间复杂度为O(n)。
算法设计技巧与分析英文版课后练习题含答案
Algorithm Design Techniques and Analysis: English VersionExercise with AnswersIntroductionAlgorithms are an essential aspect of computer science. As such, students who are part of this field must master the art of algorithm design and analysis. Algorithm design refers to the process of creating algorithms that solve computational problems. Algorithm analysis, on the other hand, focuses on evaluating the resources required to execute those algorithms. This includes computational time and memory consumption.This document provides students with helpful algorithm design and analysis exercises. The exercises are in the formof questions with step-by-step solutions. The document is suitable for students who have completed the English versionof the Algorithm Design Techniques and Analysis textbook. The exercises cover various algorithm design techniques, such as divide-and-conquer, dynamic programming, and greedy approaches.InstructionEach exercise comes with a question and its solution. Read the question carefully and try to find a solution withoutlooking at the answer first. If you get stuck, look at the solution. Lastly, try the exercise agn without referring to the answer.Exercise 1: Divide and ConquerQuestion:Given an array of integers, find the maximum possible sum of a contiguous subarray.Example:Input: [-2, -3, 4, -1, -2, 1, 5, -3]Output: 7 (the contiguous subarray [4, -1, -2, 1, 5]) Solution:def max_subarray_sum(arr):if len(arr) ==1:return arr[0]mid =len(arr) //2left_arr = arr[:mid]right_arr = arr[mid:]max_left_sum = max_subarray_sum(left_arr)max_right_sum = max_subarray_sum(right_arr)max_left_border_sum =0left_border_sum =0for i in range(mid-1, -1, -1):left_border_sum += arr[i]max_left_border_sum =max(max_left_border_sum, left_b order_sum)max_right_border_sum =0right_border_sum =0for i in range(mid, len(arr)):right_border_sum += arr[i]max_right_border_sum =max(max_right_border_sum, righ t_border_sum)return max(max_left_sum, max_right_sum, max_left_border_s um+max_right_border_sum)Exercise 2: Dynamic ProgrammingQuestion:Given a list of lengths of steel rods and a corresponding list of prices, determine the maximum revenue you can get by cutting these rods into smaller pieces and selling them. Assume the cost of each cut is 0.Lengths: [1, 2, 3, 4, 5, 6, 7, 8]Prices: [1, 5, 8, 9, 10, 17, 17, 20]If the rod length is 4, the maximum revenue is 10.Solution:def max_revenue(lengths, prices, n):if n ==0:return0max_val =float('-inf')for i in range(n):max_val =max(max_val, prices[i] + max_revenue(length s, prices, n-i-1))return max_valExercise 3: Greedy AlgorithmQuestion:Given a set of jobs with start times and end times, find the maximum number of non-overlapping jobs that can be scheduled.Start times: [1, 3, 0, 5, 8, 5]End times: [2, 4, 6, 7, 9, 9]Output: 4Solution:def maximum_jobs(start_times, end_times):job_list =sorted(zip(end_times, start_times))count =0end_time =float('-inf')for e, s in job_list:if s >= end_time:count +=1end_time = ereturn countConclusionThe exercises presented in this document provide a practical way to master essential algorithm design and analysis techniques. Solving the problems without looking at the answers will expose students to the type of problems they might encounter in real life. The document’s solutionsprovide step-by-step instructions to ensure that students can approach the problems with confidence.。
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算法设计与分析第2版吕国英第三章课后习题答案3.1//计算2+22+222+...+222 (2)void main(){int i,n,sum=0;print("请输入最后一个因子的位数\n");scanf("%d",&n);for(i=1;i<=n;i++)sum=sum+((int)pow(10,i)-1)/9*2;print("2+22+222+...+222……2=%d\n",sum); }3.2显示{5，7，4，8，9，1}的方阵方式main(){int i,j,t,ori[6]={5,7,4,8,9,1};for(i=0;i<6;i++){for(j=0;j<6;j++){t=(j-i)<0?j-i+6:j-i;printf("%d ",ori[t]);}printf("\n");}}3.3main(){int n;int **up(int **array);scanf("%d",&n);int arr[1][1]={{n*n}};for(j=1;j<n;j++)< p="">arr=up(**arr,j);}int **up(int **array,n){int upN=n+1;int[upN][upN] tem;tem[1][1]=array[1][1]-pow(n+1,2); for(i=1;i<=n;i++)tem[1][i]=tem[1][i-1]+1;for(i=1;i<=n;i++)tem[n][i]=tem[n][i-1]+1;for(i=1;i<=n;i++)tem[n][n-i]=tem[n][n+1-i]+1;for(i=1;i<n;i++)< p="">tem[1][n-i]=tem[1][n-i+1]+1 return **tem;}3.4main(){int i,j,t=0,next=1,n;printf("请输入n\n");scanf("%d",&n);printf("显示效果如下\n");for(i=1;i<=n;i++){for(j=1;j<=n-i+1;j++){if(j==1)t=next;elset=t+i+j-1;if(j==2)next=t-1;printf("%d ",t);}printf("\n");}}//思想：每一行的第二个数为next，下一行的第一个数为next-13.5main(){int n,i,j,k;int arr[100][100]={{0}};//动态定义数组太难，所以在系统直接定义一个100*100的方阵，可以处理部分小问题for(i=0;i<100;i++)for(j=0;j<100;j++)arr[i][j]=0;printf("请输入n\n");scanf("%d",&n);/*if(n%2==0){for(k=0;k<="" p="">for(i=k;i<n-k;i++)< p="">for(j=k;j<n-k;j++)< p="">arr[i][j]=k+1;}else{for(k=0;k<(n+1)/2;k++)for(i=k;i<n-k;i++)< p="">for(j=k;j<n-k;j++)< p="">arr[i][j]=k+1;}*///可将第一个for循环中的判断条件统一改为k<(n+1)/2 for(k=0;k<(n+1)/2;k++)for(i=k;i<n-k;i++)< p="">for(j=k;j<n-k;j++)< p="">arr[i][j]=k+1;printf("显示效果如下：\n")for(i=0;i<n;i++)< p="">{for(j=0;j<n;j++)< p="">printf("%2d",arr[i][j]);printf("\n");}}3.7main(){int ack(int m,int n);int m,n,score;printf("请输入ackermann函数的m，n：\n");printf("m:");scanf("%d",&m);printf("n:");scanf("%d",&n);score=ack(m,n);printf("ack(%d,%d)=%d\n",m,n,score); }int ack(int m,int n){if(m==0)return n+1;elseif(n==0)return ack(m-1,1);elsereturn ack(m-1,ack(m,n-1));}3.8main(){char str[40];int i,l,t=1;printf("Please input a string!\n"); scanf("%s",str);l=strlen(str);for(i=0;i<="" p="">if(str[i]!=str[l-i-1])t=0;if(t)printf("The string is Huiwen!\n"); elseprintf("The string is not Huiwen!\n"); }3.11main(){int i,n,sum=0;//sum为零的个数int zero(int pro);printf("此程序用于计算1*2*3*…*n所得的数末尾有多少个零。
\n");printf("请输入n(1000<n<10000):");< p="">scanf("%d",&n);for(i=1;i<=n;i++)sum=sum+zero(i);sum+=n/10;if((n%10)>5)sum++;printf("1*2*3*…*n所得的数末尾有%d个零。
\n",sum);}int zero(int pro){if(pro%1000==0)return 3;elseif(pro%100==0)return 2;elseif(pro%10==0)return 1;elsereturn 0;}3.15main(){int c,a,b;for(c=88;c<=90;c++)if((c!=88)&&(c!=90))for(a=88;a<=90;a++)if((a!=88)&&(a!=c))for(b=88;b<=90;b++)if((b!=a)&&(b!=c))printf("A<==>%c\nB<==>%c\nC<==>%c",a,b,c);}3.16main(){int num[3]={4,7,9},flag[3]={0};int n,i,sum;printf("此程序用于判断该数能否被4，7，9整除，并输出相关信息。
\n");printf("请输入n：");scanf("%d",&n);if(n%4!=0&&n%7!=0&&n%9!=0)printf("%d不能被4，7，9任一个整除。
\n",n);else{if(n%4==0)flag[0]=1;if(n%7==0)flag[1]=1;if(n%9==0)flag[2]=1;sum=flag[0]+flag[1]+flag[2];if(sum==1)printf("%d能被一个数整除，它是%d\n",n,flag[0]?num[0]:flag[1]?num[1]:num[2]);else{if(sum==3)printf("%d能同时被4，7，9整除。
\n");elseprintf("%d能被两个数整除，它是%d，%d\n",n,flag[0]?num[0]:num[1],flag[2]?num[2]:num[1]);}}}3.18int dif(int i,int j,int k,int l){if(i==j||i==k||i==l||j==k||j==l||k==l)return 0;elsereturn 1;}int dis(int m,int i,int j,int k,int l){if(m==i||m==j||m==k||m==l)return 0;elsereturn 1;}void main(){int i1,i2,i3,i4,j2,j3,j4,j5,num=0;int a,b;//a为四位数，首位应该最小为5；b为五位数，首位应为1，末尾为偶数for(i1=5;i1<10;i1++)for(i2=0;i2<10;i2++)for(i3=0;i3<10;i3++)for(i4=0;i4<10;i4++)if(dif(i1,i2,i3,i4))for(j2=0;j2<10;j2++)//首位j1为1for(j3=0;j3<10;j3++)for(j4=0;j4<10;j4++)for(j5=0;j5<10;j5+=2)//末尾j5为偶数if(dis(1,i1,i2,i3,i4)&&dis(j2,i1,i2,i3,i4)&&dis(j3,i1,i2,i3,i4)&&d is(j4,i1,i2,i3,i4)&&dis(j5,i1, i2,i3,i4)&&dis(1,j2,j3,j4,j5)) if(dif(j2,j3,j4,j5)){a=i1*1000+i2*100+i3*10+i4;b=10000+j2*1000+j3*100+j4*10+j5;if(b%a==0){num+=1;printf("第%2d个：%d = %d * 2\n",num,b,a);}}}3.19main(){char *a,*b;int n,num,i,sum,dec;printf("请输入您要输入的十六进制数的位数：n=");scanf("%d",&n);a=calloc(n,sizeof(char));for(i=0;i<n;i++)< p="">a[i]=0;/*num=(int)(n*log10(16))+1;b=calloc(num,sizeof(int));for(i=0;i<num;i++)< p="">b[i]=-1;*/printf("请输入您要转化的十六进制数\n");scanf("%s",a);sum=a[0]>=97&&a[0]<=102?a[0]-87:(a[0]>=65&&a[0]<=70?a[0]-55:a[0]-48);printf("%d\n",sum);for(i=1;i<strlen(a);i++)< p="">{dec=a[i]>=97&&a[i]<=102?a[i]-87:(a[i]>=65&&a[i]<=70?a[i]-55:a[i]-48);printf("dec=%d\n",dec);sum=sum*16+dec;printf("sum=%d\n",sum);}printf("%d",sum);}3.23main(){int i,j,l;char array[5];char number[10]={'0','1','2','3','4','5','6','7','8','9'};char num[10]={'0','1','2','3','4','5','6','7','8','9'};printf("请输入一个5位以内的正整数。