C语言程序设计第六章课后习题
C++面向对象程序设计第六章课后习题答案
第六章课后习题答案（第二版谭浩强）1://xt6-1/cpp#include <iostream> //如用VC++应改为∶#include <iosttram.h>using namespace std; //如用VC++应取消此行#include "cylinder.h"#include "point.cpp"#include "circle.cpp"#include "cylinder.cpp"int main(){Cylinder cy1(3.5,6.4,5.2,10);cout<<"\noriginal cylinder:\nx="<<cy1.getX()<<", y="<<cy1.getY()<<", r="<<cy1.getRadius()<<",h="<<cy1.getHeight()<<"\narea="<<cy1.area()<<", volume="<<cy1.volume()<<endl;cy1.setHeight(15);cy1.setRadius(7.5);cy1.setPoint(5,5);cout<<"\nnew cylinder:\n"<<cy1;Point &pRef=cy1;cout<<"\npRef as a point:"<<pRef;Circle &cRef=cy1;cout<<"\ncRef as a Circle:"<<cRef;return 0;}3:解法一#include <iostream>using namespace std;class Point{public:Point(float a,float b):x(a),y(b){}~Point(){cout<<"executing Point destructor"<<endl;}private:float x;float y;};class Circle:public Point{public:Circle(float a,float b,float r):Point(a,b),radius(r){} ~Circle(){cout<<"executing Circle destructor"<<endl;} private:float radius;};int main(){Point *p=new Circle(2.5,1.8,4.5);delete p;return 0;}3：解法二#include <iostream>using namespace std;class Point{public:Point(float a,float b):x(a),y(b){}~Point(){cout<<"executing Point destructor"<<endl;} private:float x;float y;};class Circle:public Point{public:Circle(int a,int b,int r):Point(a,b),radius(r){}~Circle(){cout<<"executing Circle destructor"<<endl;} private:float radius;};int main(){Point *p=new Circle(2.5,1.8,4.5);Circle *pt=new Circle(2.5,1.8,4.5);delete pt;return 0;}3：解法三#include <iostream>using namespace std;class Point{public:Point(float a,float b):x(a),y(b){}virtual ~Point(){cout<<"executing Point destructor"<<endl;}private:float x;float y;};class Circle:public Point{public:Circle(float a,float b,float r):Point(a,b),radius(r){}virtual ~Circle(){cout<<"executing Circle destructor"<<endl;}private:float radius;};void main(){Point *p=new Circle(2.5,1.8,4.5);delete p;}4：#include <iostream>using namespace std;//定义抽象基类Shapeclass Shape{public:virtual double area() const =0; //纯虚函数};//定义Circle类class Circle:public Shape{public:Circle(double r):radius(r){} //结构函数virtual double area() const {return 3.14159*radius*radius;};//定义虚函数protected:double radius; //半径};//定义Rectangle类class Rectangle:public Shape{public:Rectangle(double w,double h):width(w),height(h){} //结构函数virtual double area() const {return width*height;} //定义虚函数protected:double width,height; //宽与高};class Triangle:public Shape{public:Triangle(double w,double h):width(w),height(h){} //结构函数virtual double area() const {return 0.5*width*height;}//定义虚函数protected:double width,height; //宽与高};//输出面积的函数void printArea(const Shape &s){cout<<s.area()<<endl;}//输出s的面积int main(){Circle circle(12.6); //建立Circle类对象circlecout<<"area of circle =";printArea(circle);//输出circle的面积Rectangle rectangle(4.5,8.4); //建立Rectangle类对象rectanglecout<<"area of rectangle =";printArea(rectangle);//输出rectangle的面积Triangle triangle(4.5,8.4); //建立Triangle类对象cout<<"area of triangle =";printArea(triangle); //输出triangle的面积return 0;}5：#include <iostream>using namespace std;//定义抽象基类Shapeclass Shape{public:virtual double area() const =0; //纯虚函数};//定义Circle(圆形)类class Circle:public Shape{public:Circle(double r):radius(r){}//结构函数virtual double area() const {return 3.14159*radius*radius;};//定义虚函数protected:double radius; //半径};//定义Square(正方形)类class Square:public Shape{public:Square(double s):side(s){} //结构函数virtual double area() const {return side*side;} //定义虚函数protected:double side;};//定义Rectangle(矩形)类class Rectangle:public Shape{public:Rectangle(double w,double h):width(w),height(h){} //结构函数virtual double area() const {return width*height;} //定义虚函数protected:double width,height; //宽与高};//定义Trapezoid(梯形)类class Trapezoid:public Shape{public:Trapezoid(double t,double b,doubleh):top(t),bottom(t),height(h){} //结构函数virtual double area() const {return0.5*(top+bottom)*height;} //定义虚函数protected:double top,bottom,height; //上底、下底与高};//定义Triangle(三角形)类class Triangle:public Shape{public:Triangle(double w,double h):width(w),height(h){} //结构函数virtual double area()const {return 0.5*width*height;}//定义虚函数protected:double width,height; //宽与高};int main(){Circle circle(12.6); //建立Circle类对象circleSquare square(3.5); //建立Square类对象squareRectangle rectangle(4.5,8.4); //建立Rectangle类对象rectangleTrapezoid trapezoid(2.0,4.5,3.2); //建立Trapezoid类对象trapezoidTriangle triangle(4.5,8.4); //建立Triangle类对象Shape*pt[5]={&circle,&square,&rectangle,&trapezoid,&triangle};//定义基类指针数组pt，使它每一个元素指向一个派生类对象double areas=0.0; //areas为总面积for(int i=0;i<5;i++){areas=areas+pt[i]->area();}cout<<"totol of all areas="<<areas<<endl; //输出总面积return 0;}（学习的目的是增长知识，提高能力，相信一分耕耘一分收获，努力就一定可以获得应有的回报）。
C程序设计第六章答案
实验六数组练习6.2代码如下：#include <iostream>using namespace std;int main(){int num, max = 0, count = 1;//user input 6 numbersfor (int i = 0; i < 6; i++){cout << "Enter a number: ";cin >> num;//if number entered > max, max = num, count = 1 again.if (num > max){max = num;count = 1;}else if (num == max){count++;}}//displaycout << "The largest number is " << max <<endl;cout << "The largest number appears " << count << " times\n";return 0;}练习6.4代码如下：#include <iostream>using namespace std;int main (){int score[40];int upcount = 0, downcount = 0, equalcount = 0, count = 0,i = 0, j = 0, sum = 0;//input the arrays, and when user enter a minus, stop inputingdo{cout << "Please enter less than 40 students' score, if you want to stop entering you can enter a minus.\n";cout << "You have entered " << count << " scores\n";cin >> j;if ((j >= 0) && (j <= 100)){score[i] = j;j++;count++;i++;}else if (j > 100){cout << "You should enter a correct score";}}while (j >= 0);//compute the sum of the arraysfor (i = 0; i < count; i++){sum += score[i];}//compute the averageint average = sum / count;for (i = 0; i < count; i++){if (score[i] > average){upcount++;}else if (score[i] == average){equalcount++;}else if (score[i] < average){downcount++;}}//display the resultcout << "The summer scores among " << count << " students is " << sum << endl;cout << "The average scores among " << count << " students is "<< average << endl;cout << "There are(is) " << upcount << " student's(s') scores are(is) higher than average.\n";cout << "There are(is) " << equalcount << " student's(s') scores are(is) equal to average.\n";cout << "There are(is) " << downcount << " student's(s') scores are(is) lower than average.\n";return 0;}练习6.6代码如下：#include <iostream>#include <iomanip>using namespace std;bool isPrime (int num);int main (){int prime[50];for (int i = 0, num = 2; i < 50; num++){if ( isPrime(num) ){prime[i] = num;i++;}}for (int i = 0, count = 0; i < 50; i++){cout << setw(6) << prime[i];count++;if (10 == count){cout << endl;count = 0;}}system("pause");return 0;}//this function called isPrime is used to judge an integer is prime or not... bool isPrime (int num){bool isPrime = true;for (int i = 2; i <= sqrt( (double)num ); i++){if (0 == num %i){isPrime = false;break;}}return isPrime;}练习6.8代码如下：#include <iostream>using namespace std;int average(int array[], int size);double average(double array[], int size);int main (){int array1[6] = {1,2,3,4,5,6};double array2[7] = {6.0,4.4,1.9,2.9,3,4,3.5};//display the resultcout << average(array1,6) << endl << average(array2,7) << endl;return 0;}//the kind of integerint average(int array[], int size){double sum = 0;for (int i = 0; i < size; i++){sum += array[i];}return sum / size;}//the kind of integerdouble average(double array[], int size) {double sum = 0;for (int i = 0; i < size; i++){sum += array[i];}return sum / size;}练习6.10代码如下：#include <iostream>using namespace std;void min (int array[], int size);int main (){int array[8] = {2,2,4,5,10,100,2,2};min(array,8);return 0;}//打印最小元的下标void min (int array[], int size){int min = array[0];int xiabiao[10];int j = 0;for (int i = 0; i < size; i++){if ( array[i] <= min ){min = array[i];xiabiao[j] = i;j++;}}int k = j;j = 0;//保存最小元下标的个数cout << "The min of the array(s) is " << min << endl;cout << "The subscript of the minnest number is(are) ";for (; j < k; j++){cout << xiabiao[j] << endl;}}练习6.12代码如下：#include <iostream>using namespace std;void reverse (int soure[], int size);//swapvoid reverse (int soure[], int size){for (int i = 0; i < (size / 2); i++){swap ( soure[i], soure[size-1-i] );}}//check the void reverse is right or notint main (){int array[6] = {1,2,3,4,5,6};reverse (array, 6);for (int i = 0; i < 6; i++){cout << array[i] << endl;}return 0;}练习6.14代码如下：#include <iostream>#include <ctime>using namespace std;int main (){int num[100000];srand ( time(0) );for (long i = 0; i < 100000; i++){num[i] = rand();}//生成关键字int key = rand();cout << "关键字是" << key << endl;//开始计时long startTime1 = time(0);for (int i = 0; i < 100000; i++){if (key == num[i]){cout <<"关键字的下标是"<< i <<endl;}}long endTime1 = time(0);long time1 = endTime1 - startTime1;cout << "顺序搜索时间是" << time1 <<"秒\n\n";//二分搜索int low = 0;int high = 99999;//对数组进行排序,现在开始第二次计时long startTime2 = time(0);for (long i = 9999;i >= 1; i--){int xiabiao = 0, lagest = num[0];for (long j = 1;j <= i; j++){if ( num[j] > lagest ){lagest = num[j];xiabiao = j;}}//swapif ( xiabiao != i){num[xiabiao] = num[i];num[i] = lagest;}}while (high >= low){int mid = (low + high) / 2;if (key < num[mid]){high = mid - 1;}else if (key == num[mid]){cout << "关键字下标是" << mid << endl;break;}else{low = mid + 1;}}long endTime2 = time(0);long time2 = endTime2 - startTime2;cout << "排序和二分搜索花费时间是" << time2 << "秒\n\n";system("pause");return 0;}练习6.16代码如下：#include <iostream>using namespace std;void turn ( double arrays[], int size);int main (){double arrays[7] = {6.0,4.4,1.9,2.9,3.4,2.9,3.5};turn(arrays, 7);for (int i = 0; i < 7; i++){cout << arrays[i] << " ";}system("pause");return 0;}//起泡排序void turn ( double arrays[], int size){bool changed = true;do{changed = false;for (int i = 0; i < size - 1; i++){if (arrays[i] > arrays[i+1]){swap(arrays[i], arrays[i+1]);changed = true;}}} while (changed);}练习6.18代码如下：#include <iostream>using namespace std;int main (){int arrays[4][4] = {{1,2,4,5},{6,7,8,9},{10,11,12,13},{14,15,16,17}};int sum = 0;for (int i = 0, j = 0; i < 4; i++,j++){sum += arrays[i][j];}cout << "主对角线之和为" << sum << endl;system("pause");return 0;}练习6.20代码如下：#include <iostream>using namespace std;void turn ( int arrays[], int size);int main(){int time[8][7] = {{2,4,3,4,5,8,8},{7,3,4,3,3,4,4},{3,3,4,3,3,2,2},{9,3,4,7,3,4,1},{3,5,4,3,6,3,8},{3,4,4,6,3,4,4},{3,7,4,8,3,8,4},{6,3,5,9,2,7,9}};int sumofRow[8] = {0,0,0};for (int row = 0; row < 8; row++){for (int i = 0; i < 7; i++){sumofRow[row] += time[row][i];}}turn(sumofRow, 8);for (int i = 7; i >= 0; i--){cout << sumofRow[i] << endl;}system("pause");return 0;}//排序void turn ( int arrays[], int size){bool changed = true;do{changed = false;for (int i = 0; i < size - 1; i++){if (arrays[i] > arrays[i+1]){swap(arrays[i], arrays[i+1]);changed = true;}}} while (changed);}练习6.22代码如下：#include <iostream>using namespace std;//compute the sumvoid mutiplyMatrix (int a[][5],int b[][5],int c[][5],int rowsize){for (int i = 0; i < rowsize; i++){for (int j = 0; j < rowsize; j++){for (int k = 0; k < rowsize; k++){c[i][j] += (a[i][k] + b[k][j]);}}}}int main (){int a[5][5] = {{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5}};int b[5][5] = {{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5}};int c[5][5] = {{0,0,0,0,0},{0},{0},{0},{0}};mutiplyMatrix(a,b,c,5);for (int i = 0; i < 5; i++){for (int j = 0; j < 5; j++){cout << c[i][j] << endl;}}system("pause");return 0;}练习6.24代码如下：#include <iostream>#include <ctime>using namespace std;int main(){srand( time(0) );int chess[8][8];//随机输入0和1，并输出8*8列表for (int i = 0; i < 8; i++){for (int j = 0; j < 8; j++){chess[i][j] = rand() % 2;cout << chess[i][j];}cout << endl;}//计算每行的和for (int row = 0; row < 8; row++){int sumofrow = 0;for (int column = 0; column < 8; column++){sumofrow += chess[row][column];}if (0 == sumofrow){cout << "All 0s on row" << row + 1 << endl;}else if (8 == sumofrow){cout << "All 1s on row" << row + 1 << endl;}}//计算每列的和for (int column = 0; column < 8; column++){int sumofcolumn = 0;for (int row = 0; row < 8; row++){sumofcolumn += chess[row][column];}if (0 == sumofcolumn){cout << "All 0s on column" << column + 1 << endl;}else if (8 == sumofcolumn){cout << "All 1s on column" << column + 1 << endl;}}//计算两个对角线的和int sumofsubdiagonal1 = 0, sumofsubdiagonal2 = 0;for (int row = 0, column = 0; row < 8; row++,column++){sumofsubdiagonal1 += chess[row][7 - column];sumofsubdiagonal2 += chess[row][column];}if ( 0 == sumofsubdiagonal1 ){cout << "All 0s on subdiagonal1" << endl;}else if ( 8 == sumofsubdiagonal1 ){cout << "All 1s on subdiagonal1" << endl;}if ( 0 == sumofsubdiagonal2 ){cout << "All 0s on subdiagonal2" << endl;}else if ( 8 == sumofsubdiagonal2 ){cout << "All 1s on subdiagonal2" << endl;}system("pause");return 0;}练习6.26代码如下：#include <iostream>using namespace std;int factors(int num, int table[][2]){/*从i=2开始除，若不能被i整除则i++；若能被i整除则输出i，且num变成num除以i的商，重新把2赋值给i，循环。
C语言程序设计第六章数组习题及答案
1.以下对一维整型数组a的定义，正确的是_。
(2分)A.int a(10) ;B.int n = 10 , a[n] ;C.int n ;scanf( "%d" , &n ) ;int a[n] ;D.int a[10] ;2.若有定义：int a[10] ;，则对a数组元素的正确引用是_。
(2分)A.a[10]B.a[3.5]C.a(5)D.a[10-10]3.对定义int a[10] = {6 , 7 , 8 , 9 , 10} ; 的正确理解是_。
(2分)A.将5个初值依次赋给a[1]--a[5]B.将5个初值依次赋给a[0]--a[4]C.将5个初值依次赋给a[6]--a[10]D.因为数组长度与初值个数不相同，所以此语句不正确4..若有定义：int a[3][4]; , 则对a数组元素的正确引用是_。
(2分)A.a[3][4]B.a[1,3]C.a[1+1][0]D.a(2)(1)5.以下对二维数组a初始化正确的语句是_。
(2分)A.int a[2][ ]={{0 , 1 , 2}, {3 , 4 , 5}};B.int a[ ][3]={{0, 1, 2}, {3, 4, 5}};C.int a[2][4]={{0, 1 , 2}, {3 , 4}, {5}};D.int a[ ][3]={{0, 1, 2}, { }, {3, 4}};6.对二维数组a进行如下初始化：int a[ ][3]={0 , 1 , 2 , 3 , 4 , 5};则a[1][1]的值是_。
(2分)A.0B.3C.4D.17.下面程序段的运行结果是_。
(2分)#include<stdio.h>int main( ){int i , x[3][3] = {1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9} ;for( i = 0 ; i < 3 ; i++ )printf( "%2d" , x[i][2-i] ) ;return 0 ;}A.1 5 9B.1 4 7C.3 5 7D.3 6 98.以下对数组s的初始化，错误的是_。
C语言程序设计第四版第六章答案_谭浩强
C语言程序设计第四版第六章答案_谭浩强1、用筛选法求100之内的素数。
解：#include#includeint main(){int i,j,n,a[101];for (i=1;i<=100;i++)a[i]=i;a[1]=0;for (i=2;i<sqrt(100);i++)< bdsfid="73" p=""></sqrt(100);i++)<>for (j=i+1;j<=100;j++){if(a[i]!=0 && a[j]!=0)if (a[j]%a[i]==0)a[j]=0;}printf("\");for (i=2,n=0;i<=100;i++){ if(a[i]!=0){printf("%5d",a[i]);n++;}if(n==10){printf("\");n=0;}}printf("\");return 0;}2、用选择法对10整数排序。
解：#includeint main(){int i,j,min,temp,a[11];printf("enter data:\");for (i=1;i<=10;i++){printf("a[%d]=",i);scanf("%d",&a[i]);}printf("\");printf("The orginal numbers:\");for (i=1;i<=10;i++)printf("%5d",a[i]);printf("\");for (i=1;i<=9;i++){min=i;for (j=i+1;j<=10;j++)if (a[min]>a[j]) min=j;temp=a[i];a[i]=a[min];a[min]=temp;}printf("\The sorted numbers:\");for (i=1;i<=10;i++)printf("%5d",a[i]);printf("\");return 0;}3、求一个3×3的整型矩阵对角线元素之和。
C语言程序设计 – 第 06 章课后习题
C语言程序设计– 第六章课后习题电子13-02班王双喜一、选择题1. C语言中一维数组的定义方式为：类型说明符数组名（C）A. [整型常量]B. [整型表达式]C. [整型常量]或[整型常量表达式]D. [常量表达式]2. C语言中引用数组元素时，下标表达式的类型为（C）A. 单精度型B. 双精度型C. 整型D. 指针型3. 若有定义：int a[3][4];，则对a数组元素的非法引用是（D）A. a[0][3*1]B. a[2][3]C. a[1+1][0]D. a[0][4]（解释：A、B、C均正确，D看起来引用不太妥当，但其亦有其意义（a[0][4]等价于a[1][0]））4. 若有定义：int a[][3] = {1, 2, 3, 4, 5, 6, 7, 8, 9};，则a数组的第一维大小是（C）A. 1B. 2C. 3D. 4（解释：共9个元素，除以3即可得第一维大小是3；若有余数，则应加1）5. 若有定义：int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};，则值为5的表达式是（C）A. a[5]B. a[a[4]]C. a[a[3]]D. a[a[5]]6. 要求定义包含8个int类型元素的一维数组，以下错误的定义语句是（A）A. int N = 8;int a[N]; B. #define N 3while (a[2*N+2];C. int a[] = {0, 1, 2, 3, 4, 5, 6, 7};D. int a[1+7] = {0};（解释：数组的大小必须是整型常量或整型常量表达式）7. 若二维数组a有m列，则在a[i][j]前的元素个数为（A）A. i * m + jB. j * m + iC. i * m + i - 1D. i * m + j - 18. 下面是对数组s的初始化，其中不正确的是（D）A. char s[5] = {"abc"};B. char s[5] = {'a', 'b', 'c'};C. char s[5] = "";D. char s[5] = "abcdef";（解释：D中元素个数太多，算上'\0'共六个，非法）9. 下面程序段的运行结果是（B）char c[] = "\t\v\\\0will\n";printf("%d", strlen(c));A. 14B. 3C. 9D. 字符串中有非法字符，输出值不确定（解释：字符串中第四个是'\0'即结束标志，因此字符串长度是3）10. 判断字符串s1是否等于s2，应当使用（D）A. if (s1 == s2)B. if (s1 = s2)C. if (strcpy(s1, s2))D. if (strcmp(s1, s2) == 0)（解释：对于字符串来讲，其名字的内容是该字符串的起始地址，不能通过比较名字来比较相等，而应该用专用的函数进行逐字符匹配）二、写出程序的执行结果1. 程序一：# include <stdio.h>main(){int a[3][3] = {1, 3, 5, 7, 9, 11, 13, 15, 17};int sum = 0, i, j;for (i = 0; i < 3; i++)for (j = 0; j < 3; j++){a[i][j] = i + j;if (i == j) sum = sum + a[i][j];}printf("sum = %d", sum);}执行结果：打印sum = 6.（解释：a中各个元素的值是其行和列数字之和，sum内保存a中对角线元素之和，即sum = 0 + 2 + 4）2. 程序二：# include <stdio.h>main(){int i, j, row, col, max;int a[3][4] = {{1, 2, 3, 4}, {9, 8, 7, 6}, {-1, -2, 0, 5}};max = a[0][0]; row = 0; col = 0;for (i = 0; i < 3; i++)for (j = 0; j < 4; j++)if (a[i][j] > max){max = a[i][j];row = i;col = j;}printf("max = %d, row = %d, col = %d\n", max, row, col);}执行结果：打印max = 9, row = 1, col = 0.（解释：此程序的功能是逐行逐列扫描元素，总是将最大的元素赋给max，并保存该元素的行数和列数；因此执行完毕后，max是最大的元素(9)，row是其行数(1)，col是其列数(0)）3. 程序三：# include <stdio.h>main(){int a[4][4], i, j, k;for (i = 0; i < 4; i++)for (j = 0; j < 4; j++)a[i][j] = i - j;for (i = 0; i < 4; i++){for (j = 0; j <= i; j++)printf("%4d", a[i][j]);printf("\n");}}执行结果：第一行打印0；第二行打印1 0；第三行打印2 1 0；第四行打印3 2 1 0。
C程序设计（第五版）-第6章利用数组处理批量数据课后习题答案
C程序设计（第五版）-第6章利⽤数组处理批量数据课后习题答案1.⽤筛选法求100质数⼜称素数。
⼀个⼤于1的⾃然数，除了1和它⾃⾝外，不能被其他⾃然数整除的数叫做质数；否则称为合数（规定1既不是质数也不是合数）先解释⼀下筛选法的步骤：<1> 先将1挖掉(因为1不是素数)。
<2> ⽤2去除它后⾯的各个数，把能被2整除的数挖掉，即把2的倍数挖掉。
<3> ⽤3去除它后⾯的各数，把3的倍数挖掉。
<4> 分别⽤5…各数作为除数去除这些数以后的各数。
上述操作需要⼀个很⼤的容器去装载所有数的集合，只要满⾜上述条件，即2的倍数⼤于1的全部置0，3的倍数⼤于1的全部置0，4的倍数⼤于1的全部置0……⼀直到这个数据集合的末尾，这样⼀来不为0的数就是素数了，然后按下标在⾥⾯进⾏查找就好了1#include <stdio.h>2#include <windows.h>3int main()4{5printf("------------------\n");6int i, j, k, a[100];7// 先给100个数赋值8for (i = 0; i < 100; i++)9{10a[i] = i + 1;11}1213// 1不是质数也不是合数14a[0] = 0;1516for (i = 0; i < 100; i++)17{18for (j = i + 1; j < 100; j++)19{20// 把后⾯的数能整除前⾯的数赋值为021if (a[i] != 0 && a[j] != 0)22{23if (a[j] % a[i] == 0)24{25a[j] = 0; //把不是素数的都赋值为026}27}28}29}3031// 打印质数，每10个换⾏32for (i = 0; i < 100; i++)33{34if (k % 10 == 0)35{36printf("\n");37}38if (a[i] != 0)39{40printf("%d ", a[i]);41k++;42}43}4445return 0;46}2.⽤选择法对101#include <stdio.h>2#include <windows.h>3int main()4{5printf("请输⼊10个数：\n");6int minIndex, temp, a[10];78for (int i = 0; i < 10; i++)9{10scanf("%d", &a[i]);11}1213for (int i = 0; i < 10; i++)14{15minIndex = i;16for (int j = i + 1; j < 10; j++)17{18if (a[j] <= a[minIndex])19{20minIndex = j;21}22}2324temp = a[i];25a[i] = a[minIndex];26a[minIndex] = temp;27}2829printf("排序后结果：\n");3031for (int i = 0; i < 10; i++)32{33printf("%d ", a[i]);34}35return 0;36}3.求⼀个3*31#include <stdio.h>2#include <windows.h>3int main()4{5printf("请输⼊元素：\n");6int x, y, z, a[3][3];7for (int i = 0; i < 3; i++)8{9for (int j = 0; j < 3; j++)10{11scanf("%d", &a[i][j]);12}13}14printf("输出刚刚输⼊的元素：\n");15for (int i = 0; i <= 2; i++)16{17for (int j = 0; j <= 2; j++)18{19printf("%d\t", a[i][j]);20}2122printf("\n");23}24printf("\n");25// 计算对⾓线的合26for (int i = 0; i < 3; i++)27{28x += a[i][i];29}3031for (int i = 0, j = 2; i < 3; i++, j--)32{33y += a[i][j];34}35z = x + y;36printf("左上到右下对⾓线的合：%d\n", x); 37printf("右上到左下对⾓线的合：%d\n", y); 38printf("两条对⾓线之合：%d\n", z);39// 结果40// 请输⼊元素：41// 1 2 3 4 5 6 7 8 942// 输出刚刚输⼊的元素：43// 1 2 344// 4 5 645// 7 8 94647// 左上到右下对⾓线的合：1548// 右上到左下对⾓线的合：3149// 两条对⾓线之合：4650return 0;51}4.1#include <stdio.h>2#include <windows.h>3int main()4{5printf("------------------\n");6int t, x, a[5] = {1, 2, 4, 5, 6};78printf("请输⼊需要插⼊的数字：\n");9scanf("%d", &x);10for (int i = 0; i < 5; i++)11{12if (x < a[i])13{14t = a[i];15a[i] = x;16x = t;17}18printf("%3d", a[i]);19}20printf("%3d", x);2122return 0;23}5.讲⼀个数组的值按逆序重新存放。
C语言程序设计教程第六章课后习题参考答案
C语⾔程序设计教程第六章课后习题参考答案P158 1求三个实数最⼤值#includefloat max(float,float,float);int main(){float a,b,c,m;printf("请输⼊三个实数:");scanf("%f %f %f",&a,&b,&c);printf("最⼤数为%f\n",max(a,b,c));return 0;}float max(float a,float b,float c){float t;if(a>b&&a>c)t=a;else if(b>a&&b>c)t=b;elset=c;return t;}P158 2求最⼤公约数最⼩公倍数#includeint fun1(int a,int b);int fun2(int a,int b);int main(){int a,b;printf("请输⼊两个整数:");scanf("%d %d",&a,&b);printf("最⼤公约数为:%d\n",fun1(a,b));int t,r;if(a{t=a;a=b;b=t;}while((r=(a%b))!=0) {a=b;b=r;}return b;}int fun2(int a,int b) {int n;n=(a*b)/fun1(a,b); return n;}P158 3求完全数#includevoid wan(int n); void main(){int n;for(n=1;n<1000;n++) wan(n);printf("\n");}void wan(int n){if(n%i==0)s=s+i;}if(n==s)printf("%d\t",n); }P158 4⽆暇素数#include#includeint nixvshu(int n);int isPrime(int n);int main(){int n,t;printf("⽆暇素数:\n");for(n=100;n<=999;n++) {t=nixvshu(n);if(isPrime(n)&&isPrime(t)) printf("%d\t",n);}printf("\n");return 0;}int nixvshu(int n){int x=0;while(n){x=x*10+n%10;n=n/10;}return x;int i;for(i=2;i<=sqrt(n);i++)if(n%i==0) return 0;return n;}P158 7递归函数#includeint Y(int n){if(n==0)return 0;if(n==1)return 1;if(n==2)return 2;elsereturn (Y(n-1)+Y(n-2)+Y(n-3)); } int main(){int n,k=0;for(n=0;n<=19;n++){printf("%d\t",Y(n));k++;if(k%5==0)printf("\n");}return 0;}P124 6分解质因数#include#includevoid fenjie(int );int main(){int n;printf("请输⼊⼀个正整数:"); scanf("%d",&n);if(isPrime(n)){printf("%d=1*%d\n",n,n);}else{fenjie(n);printf("\n");}return 0;}int isPrime(int n){int i;for(i=2;i<=sqrt(n);i++){if(n%i==0) return 0;}return 1;}int zhi(int n){int m;for(m=2;m<=n;m++){if(isPrime(m)&&(n%m==0)) break;void fenjie(int n){int m;printf("%d=%d",n,zhi(n));while(n>zhi(n)){m=zhi(n);n=n/m;printf("*%d",zhi(n));}}P47 1输出闰年#includeint f(int year);int main(){int year,k=0;for(year=1900;year<=2000;year++){if(f(year)){printf("%d\t",year);k++;if(k%5==0)printf("\n");}}return 0;}int f(int year){if((year%4==0&&year%100!=0)||(year%400==0)) return year;P47 2输出回⽂数#includeint fun(int n);int main(){int n,k=0;for(n=10;n<=2000;n++) {if(n == fun(n)){printf("%d\t",n);k++;if(k%5==0)printf("\n");}}return 0;}int fun(int n){int i=0;while(n>0){i=i*10+n%10;n=n/10;}return i;}P47 3进制转换#includevoid trans(int n,int base); int main()printf("请输⼊要转换的⼗进制数："); scanf("%d",&n);printf("请输⼊转换的进制："); scanf("%d",&base);trans(n,base);printf("\n");return 0;}（⽅法⼀）void trans(int n,int base){if(n){trans(n/base,base);if(n%base>=10)switch(n%base){case 10:printf("A");break;case 11:printf("B");break;case 12:printf("C");break;case 13:printf("D");break;case 14:printf("E");break;case 15:printf("F");break;}elseprintf("%d",n%base);}}（⽅法⼆）void trans(int n,int base){int r;char c;trans(n/base,base); r=n%base;if(r>=10)c='A'+r-10;elsec='0'+r;printf("%c",c);}}。
c语言教学资料—第6章课后答案.docx
第6章练习与思考1.指针变量有哪几种运算类型？除了一般变量能做的它都能做以外，还有取地址和取内容运算。
2.有一个4x4的矩阵，试用指针变量按照4行4列格式，输岀矩阵中各元素的值。
#include "stdio.h"void main(){int 询4][4]={{1,1丄1},{1丄1,1},{1丄1,1},{1,1,1,1}};int *p=a;for(i=0;i<4*4;i++){ printf(n%3d",*(p+i));if((i+l)%4=0)printf(H\n H);}}3•输出一个字符串，将这个字符串屮大写字母改为小写字母，第一个字母变大写。
#include "stdio.h"void main(){char a[100],*p 二NULL;int i;printf(n Please input a string:\n H);gets(a);P=a;if(*p>=,a,&&*p<=,z,)*p=*p・32;for(i=l;a[i]!='\O f;i++){if(*(p+i)>='A '&&*(p+i)v=Z) *(p+i)=*(p+i)+32;}puts(a);}4.指向函数的指针有哪些特点？(1)可以通过调用指向函数的指针来调用函数。
(2)对于已定义的函数指针可以指向返回值类型相同的不同函数。
(3)函数指针可做函数的参数。
5.编写程序，在己知字符串str中截取一子串。
要求该子串是从血的第m个字符开始, 由n个字符组成。
#include "stdio.h"void main()char str[100],s[100];char *pl=str,*p2=s;int i,m,n;printf(n please input string:\n");scanf(n%s n,str);printf(”please input m,n:\n n);scanf("%d,%d",&m,&n);for(i=0;i<n;i++)*(p2+i)=*(pl+m+i);for(i=0;*(p2+i)U\0：i++) prin(f(”％c”,*(p2+i));}6.编写程序，利用指针将二维数组屮各元素输出。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
习题4 已知5个学生的4门课成绩，要求求出每个 学生的平均成绩，然后对平均成绩从高到低将 各学生的成绩排序记录（成绩最高的学生排在 数组最前面的行，成绩最低的学生排在数组最 后面的行）
#include <stdio.h> void main () { int i,j,k; float a[5][5]={{78,79,90,67},{60,76,89,63}, {86,75,96,56},{54,63,86,96}, {63,96,98,97}}; float sum,t; for(i=0;i<5;i++) { for(j=0;j<5;j++) printf("%12f",a[i][j]); printf("\n"); } for(i=0;i<5;i++) { sum=0; for(j=0;j<4;j+][4]=sum/4; }
习题6 有15个数按由大到小顺序存放在一个数组 中，输入一个数，要求用折半查找法找出该数 是数组中第几个元素的值。如果该数不在数组 中，则输出“无此数”。
#include<stdio.h> int main() { int a[15]={15,14,13,12,11,10,9,8,7,6,5,4,3,2,1}; int key,mid,star=0,end=15-1; printf("enter a look for number:\n"); scanf ("%d",&key); if(key>a[0]||key<a[end]) { printf("无此数\n");} else { while(star<=end) { mid = (star+end)/2; if(key==a[mid]) { printf("这个数在第%d\n",mid);break;} else if(key>a[mid]) {end=mid-1;} else {star=mid+1;} } if(star>end) { printf("无此数\n");} } }
for(k=0;k<4;k++) for(i=0;i<4-k;i++) if(a[i][4]<a[i+1][4]) for(j=0;j<5;j++) {t=a[i][j];a[i][j]=a[i+1][j];a[i+1][j]=t;} for(i=0;i<5;i++) { for(j=0;j<5;j++) printf("%12f",a[i][j]); printf("\n"); } }