C++面向对象程序设计第六章课后习题答案

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面向对象程序设计第六章练习与思考题参考解答

BLACK=1,
BLUE//此处BLUE的值也为2，和WHITE重复，应改为除2之外的自他值比如（BLUE=3）
};//此处分号;不可缺少
//enum类型名{常量1,常量2,…,常量n};默认情况下常量1的值为0，常量2的值为1，依次//类推；若常量2被赋值为m，则常量3的值为m+1;（常量3未赋值情况下）。
}
row+=2;
if(row>magic_len)row-=magic_len;
col--;
if(col<1)col+=magic_len;
}
return 1;
}
int print_magic(int magic[][MAX_LEN],int magic_len)
{
int row,col;
cout<<"Find "<<magic_len<<"*"<<magic_len<<" magic matrix:\n";
（3）int int_array[10];
int * int_ptr=new int[10];
int_array++;int_ptr++;//int_array是整型数组名，是个常量指针，不能自加操作
int_array=int_ptr//int_ptr是指针变量，而int_array是常量指针，不能对常量指针赋值
while(* ptr){//指针已经指向了字符串尾结束标志’\0’，
cout<<*ptr;//下一次循环时，while循环条件为假，所以
ptr=ptr+1;//不执行循环体内语句。

C面向对象程序设计课后习题答案1~14章

c1=getchar(); //将输入的第一个字符赋给c1
c2=getchar(); //将输入的第二个字符赋给c2
cout<<"用putchar函数输出结果为:";
putchar(c1);
putchar(44);
putchar(c2);
cout<<endl;
cout<<"用cout语句输出结果为:";
putchar(c2);
cout<<endl;
cout<<"用cout语句输出结果为:";
cout<<c1<<c2<<endl;
return 0;
}
3-4-1、#include <iostream>
using namespace std;
int main ( )
{char c1,c2;
cout<<"请输入两个字符c1,c2:";
cout<<"please enter score of student:";
cin>>score;
while (score>100||score<0)
{cout<<"data error,enter data again.";
cin>>score;
}
switch(int(score/10))
{case 10:
else m=y;
if (z<m) m=z;
return(m);
}
1-8、#include <iostream>

C面向对象程序设计课后习题答案第版谭浩强

C面向对象程序设计课后习题答案第版谭浩强文件排版存档编号：[UYTR-OUPT28-KBNTL98-UYNN208]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 {return 0.5*(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;}。

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。

面向对象程序设计 C 山师第六章习题答案

第六章习题答案一、选择填空1、A2、C3、D4、B5、D6、A7、C8、A9、D 10、A 11、C 12、A13、B 14、C 15、C 16、D 17、B 18、C 19、A 20、D21、C 22、B二、判断下列描述的正确性，对者划√，错者划×。

1、√2、×3、×4、×5、√6、√7、×8、√9、× 10、√11、√ 12、√ 13、√ 14、√ 15、× 16、√ 17、√ 18、√ 19、√ 20、×21、× 22、×三、分析下列程序的输出结果。

1、运行该程序输出结果如下所示。

Default constructor calledConstructor calleda=0,b=0a=4,b=82、运行该程序输出结果如下所示。

a=7,b=93、运行该程序输出结果如下所示。

1044、运行该程序输出结果如下所示。

1035，789.5045、运行该程序输出结果如下所示。

1{}{0，1，2，3，4，5，6，7，8}1{11，12，13，14，15，16，17，18，19}{19，18，17，16，15，14，13，12，11}6、运行该程序输出结果如下所示。

Starting1:Default constructor called.Default constructor called.Default constructor called.Eding1:Starting2:Constructor: a=5,b=6Constructor: a=7,b=8Constructor: a=9,b=10Ending2:Destructor called.a=9,b=10Destructor called.a=7,b=8Destructor called.a=5,b=6Destructor called.a=5,b=6Destructor called.a=3,b=4Destructor called.a=1,b=27、运行该程序输出结果如下所示。

《C语言程序设计教程》(第三版)课后习题参考答案

C语言程序设计课后习题参考答案习题一一、单项选择题1、C2、B3、B4、C5、D6、A7、C8、A二、填空题1、判断条件2、面向过程编程3、结构化4、程序5、面向对象方法6、基本功能操作、控制结构7、有穷性8、直到型循环结构9、算法10、可读性11、模块化12、对问题的分解和模块的划分习题二一、单项选择题1、B2、D3、C4、B5、A6、A7、B8、C二、填空题1、主2、C编译系统3、结构化4、程序5、面向对象方法6、.OBJ7、库函数8、直到型循环结构习题三一、单项选择题1、D2、B3、A4、C5、A6、D7、B8、D9、B 10、C 11、A 12、D 13、C 14、B 15、C 16、A17、B 18、C 19、C 20、D 21、A 22、D 23、D 24、D、A25、D 26、A二、填空题1、补码2、10^-138~10^138、15~163、实4、单目运算符、自右向左5、函数调用6、65,89习题四一、单项选择题1、D2、C3、D4、A5、D6、B7、A8、C9、B 10、B二、填空题1、两, ；2、5.1690003、-200 2500、i=-200，j=2500回车、i=-200回车j=2500回车4、a=98，b=765.000000，c=4321.0000005、100 25.81 1.89234、100,25.81,1.89234、100回车25.81回车1.89234回车6、0，0，37、38、scanf(“%lf %lf %lf”,&a,&b,&c);9、13 13.000000 13.00000010、c=b-a;a=b+c;习题五一、单项选择题1、B2、D3、C4、B5、B6、D7、A8、B9、D二、填空题1、1 、02、k！=03、if（x>4||x<-4）printf(“%d”,x);else printf(“error!”);4、if(((x>=1&&x<=10)||(x>=200&&x<=210))&&(x%2!=0))Printf(“%d”,x);5、16、17、10!Right!8、a=09、2,110、0<a<b习题六一、单项选择题1、B2、C3、C4、B5、C6、B7、C8、A二、填空题1、无穷次2、83、204、115、3.66、*#*#*#$7、8 5 28、d=1.0 、k++、k<=n9、！（x<0）、x<amin习题七一、单项选择题1、B2、D3、C4、C5、A6、A7、D8、A二、填空题1、1 2 4 8 16 32 64 128 256 5122、a[age]++、i=18;i<263、break、i==84、a[i]>b[i]、i<3、j<55、b[j]=0、b[j]=a[j][k]习题八一、单项选择题1、B2、C3、C4、A5、A6、A7、C8、D9、D 10、B 11、A 12、C 13、A 14、C 15、B二、填空题1、return 1、return n+sum(n-1)2、return 1、n*facto(n-1)习题九一、单项选择题1、D2、C3、D4、A5、C6、C7、C8、C9、B 10、C 11、A 12、C 13、B 14、A 15、D 16、B17、C 18、A 19、B 20、C二、填空题1、int 、return z2、*p++3、’\0’、++4、p、max<*q、min>*q习题十一、单项选择题1、D2、D3、A4、5、B6、A7、C8、B9、D 10、11、C 12、D 13、D 14、C二、填空题1、34 122、ARRAY a[10],b[10],c[10];3、2 34、ab、cd5、（*b）.day、b->day6、adabc defghi mnohi no7、（struct node *）、！=’\n’、p=top;8、p1=p1->next9、（struct list *）、(struct list *)、return (n)习题十一一、单项选择题1、A2、A3、B4、A5、B6、D7、B8、A9、A 10、B 11、B 12、B 13、C 14、C 15、D 16、A17、D二、填空题1、ASCII(文本)、二进制2、pf=fopen(“A:\\zk04\\data\\txfile.dat”,”w”);3、fputc()、fputs()、fscanf()、fread()4、（后两个空）文件结束符、非0值。

c面向对象程序设计课后习题答案

c面向对象程序设计课后习题答案C面向对象程序设计课后习题答案在学习C面向对象程序设计课程的过程中，课后习题是巩固知识、提升能力的重要途径。

通过认真完成习题，我们可以更好地理解课程内容，掌握编程技巧，提高解决问题的能力。

下面我们将针对一些常见的C面向对象程序设计课后习题进行答案解析。

1. 请编写一个C++程序，实现一个简单的学生信息管理系统，包括学生姓名、学号、成绩等信息的录入、查询和修改功能。

答案解析：首先，我们需要定义一个学生类，包括姓名、学号、成绩等属性，并实现相应的方法来实现信息的录入、查询和修改功能。

然后在主函数中创建学生对象，调用相应的方法即可实现学生信息管理系统。

2. 编写一个C++程序，实现一个简单的图书管理系统，包括图书名称、作者、出版社等信息的录入、查询和删除功能。

答案解析：同样地，我们需要定义一个图书类，包括图书名称、作者、出版社等属性，并实现相应的方法来实现信息的录入、查询和删除功能。

在主函数中创建图书对象，调用相应的方法即可实现图书管理系统。

3. 设计一个C++程序，模拟实现一个简单的银行账户管理系统，包括账户余额、存款、取款等功能。

答案解析：在这个问题中，我们需要定义一个银行账户类，包括账户余额、存款、取款等属性，并实现相应的方法来实现账户管理系统。

在主函数中创建账户对象，调用相应的方法即可实现银行账户管理系统。

通过以上习题的解答，我们可以看到C面向对象程序设计的重要性和实际应用。

通过不断地练习和实践，我们可以更好地掌握面向对象程序设计的知识和技能，提高编程能力，为今后的工作和学习打下坚实的基础。

希望同学们能够认真对待课后习题，不断提升自己的编程水平。

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。

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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）。