C++程序设计习题答案第六章

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）。

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。

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。

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_。

习题及实验解答第六章一、选择题1、应为4（无正确选项）2、D3、B C4、D5、A6、A7、C8、B9、A 10、A二、程序填空1、stu[i].score k=j p[k]=p[i] p[i]=temp2、p!=NULL p->data p->next3、struct node * s->data=ch r=s NULL三、编程题1、#include "iostream.h"struct staff{char num[6];char name[8];float salary[3]; //分项工资float gs; //实得工资}s[100];void main( ){int i,j,n;cin>>n; /*输入职工人数*/for(i=0;i<n;i++){cin>>s[i].num>>s[i].name;for(j=0;j<3;j++)cin>>s[i].salary[j];}cout<<"NO. salary\n";for(i=0;i<n;i++){s[i].gs= s[i].salary[0]+ s[i].salary[1]- s[i].salary[2] ;cout<<s[i].num<<'\t'<<s[i].gs<<endl;}}2、#include "iostream.h"#include "stdio.h"struct str{char ch;struct str *next;};void main(){char s[100];int i=0,num=0;struct str *insert,*head=NULL,*p;gets(s);while(s[i]!='\0'){insert=new str;insert->ch=s[i];if(head==NULL){head=insert ;head->next=NULL;}else{insert->next=head ;head=insert;}i++;}p=head;while(p!=NULL){if(p->ch>='A'&&p->ch<='Z')num++;cout<<p->ch;p=p->next;}cout<<endl<<"num="<<num<<endl; }3、#include "iostream.h"#include "stdio.h"struct node{char ch;int count;struct node *next;};void main( ){struct node *head,*p1,*p2,*insert;char c;head=NULL;while((c=getchar())!='\n'){p1=head;while(p1!=NULL&&c>p1->ch){p2=p1;p1=p1->next;}if(p1==NULL){insert=new node;insert->ch=c;insert->count=1;if(head==NULL){insert->next=head;head=insert;}else{insert->next=NULL;p2->next=insert;}}else if(c==p1->ch)p1->count++;else{insert=new node;insert->ch=c;insert->count=1;if(p1==head){insert->next=head;head=insert;}else{insert->next=p1;p2->next=insert;}}}p1=head;while(p1!=NULL){cout<<p1->ch<<' '<<p1->count<<'\t';p1=p1->next;}}4、#include "stdio.h"#include "iostream.h"struct node{int coef;int expn;struct node *next;};struct node *creat(){struct node *head,*tail,*p;int c,e;head=NULL;cin>>c>>e;while(c!=0) //约定以输入系数为0作为多项式的结束{p=new node;p->coef=c;p->expn=e;if(head==NULL)head=p;elsetail->next=p;tail=p;cin>>c>>e;}tail->next=NULL;return head;}void print(struct node *h){struct node *p;p=h;while(p!=NULL){if(p->next!=NULL)cout<<p->coef<<'x'<<p->expn<<'+';else{if(p->coef!=0&&p->expn!=0)cout<<p->coef<<'x'<<p->expn<<endl;else if(p->coef!=0)cout<<p->coef<<endl;elsecout<<endl;}p=p->next;}}void main(){struct node *h1,*p1,*h2,*p2,*h3,*p3,*newnode,*t3;h1=creat();print(h1);h2=creat();print(h2);p2=h2;h3=NULL;p1=h1;p2=h2;p3=h3;t3=h3;while(p1!=NULL&&p2!=NULL){newnode=new node;if(p1->expn>p2->expn){newnode->coef=p1->coef;newnode->expn=p1->expn;p1=p1->next;}else if(p1->expn<p2->expn){newnode->coef=p2->coef;newnode->expn=p2->expn;p2=p2->next;}else{newnode->coef=p2->coef+p1->coef;newnode->expn=p2->expn;p2=p2->next;p1=p1->next;}if(h3==NULL){h3=newnode;t3=newnode;}elset3->next=newnode;t3=newnode;}if(p1==NULL)t3->next=p2;elset3->next=p1;print(h3);}第七章一、选择题1、D2、B3、B4、A5、B6、A7、D8、B9、C 10、B二、程序填空1、fname, “w”(ch=getchar())!=’#’count++2、(c=fgetc(fp)) length++ length=03、”wb”&emp, sizeof(employer),1,fp fclose(fp) “rb”&emp, sizeof(employer),1,fp三、编程题1、#include "iostream.h"#include "stdlib.h"#include "stdio.h"void main(){FILE *fp1,*fp2;char ch;fp1=fopen("f1.txt","a");if(fp1==NULL){cout<<"can't open f1.\n";exit(1);}if((fp2=fopen("f2.txt","r"))==NULL){cout<<"can't open f2.\n";exit(1);}while(1){ch=fgetc(fp2);if(feof(fp2))break;cout<<ch;fputc(ch,fp1);}fclose(fp1);fclose(fp2);}2、#include "iostream.h"#include "stdlib.h"#include "stdio.h"void main(){FILE *fp;int a[10],i,j;if((fp=fopen("d1.dat","w"))==NULL){cout<<"can't open d1.\n";exit(1);}for(i=0;i<10;i++)a[i]=rand();for(i=0;i<9;i++)for(j=0;j<9-i;j++)if(a[j]<a[j+1]){int t=a[j];a[j]=a[j+1];a[j+1]=t;}for(i=0;i<10;i++)fprintf(fp,"%d\t",a[i]);fclose(fp);}3、#include "iostream.h"#include "stdlib.h"#include "stdio.h"#include "string.h"void main(){FILE *fp;char s[100];int a[26]={0},i;if((fp=fopen("f.txt","r"))==NULL){cout<<"can't open f.\n";exit(1);}fgets(s,100,fp);strlwr(s);i=0;while(s[i]!='\0'){if(s[i]>='a'&&s[i]<='z')a[s[i]-'a']++;i++;}for(i=0;i<26;i++)cout<<(char)('a'+i)<<":"<<a[i]<<endl;fclose(fp);}4、#include "iostream.h"#include "stdlib.h"#include "stdio.h"struct student{char num[8];char name[20];double s[3],ave;}st[5];void main(){student stu[5];FILE *fp;int i;if((fp=fopen("stu","wb"))==NULL){cout<<"can't open stu.\n";exit(1);}for(i=0;i<5;i++){cin>>stu[i].num>>stu[i].name>>stu[i].s[0]>>stu[i].s[1]>>stu[i].s[2];stu[i].ave=(stu[i].s[0]+stu[i].s[1]+stu[i].s[2])/3;}fwrite(stu,sizeof(student),5,fp);fclose(fp);}第八章一、选择题1、A2、A3、C4、C5、6、D7、B8、D9、C 10、B11、D 12、A 13、B 14、D 15、D二、阅读程序写结果1、con1 calledcon2 calledcon3 calleda=0,b=0a=10,b=10a=10,b=202、0 51 52 53 54 53、4564、10,106,67,95、x=0x=10x=7三、编程题1、#include "iostream.h"#include "string.h"class Cat{private:int age;double weight;char color[10];public:void set(int a,double w,char c[10]){age=a;weight=w;strcpy(color,c);}void print(){cout<<"age:"<<age<<"\tweight:"<<weight<<"\color:"<<color<<endl;}int getage(){return age;}double getweight(){return weight;}char *getcolor(){return color;}};void main(){Cat c1;int a;double w;char c[10];cin>>a>>w>>c;c1.set(a,w,c);c1.print();}2、#include "iostream.h"#include "string.h"#include "stdio.h"class Mystring{private:char *str;public:Mystring(){ }Mystring(char *s){str=new char[100];strcpy(str,s);}void set(char *s){str=new char[100];strcpy(str,s);}void print(){cout<<str<<endl;}int length( ){int i=0;while(str[i]!='\0')i++;return i;}char *stringcat(Mystring s2){int i=0,j=0;while(str[i]!='\0')i++;while(s2.str[j]!='\0')str[i++]=s2.str[j++];str[i]='\0';return str;}};void main(){Mystring s1;char s[100];gets(s);s1.set(s);s1.print();gets(s);Mystring s2(s);s2.print();cout<<s1.stringcat(s2);}3、#include "iostream.h"#include "string.h"#include "stdio.h"class Point{private:double x,y;public:Point(){ }Point(double x1,double y1){x=x1;y=y1;}void set(double x1,double y1){x=x1;y=y1;}void move(double x1,double y1){x=x+x1;y=y+y1;}void print(){cout<<"("<<x<<","<<y<<")"<<endl;}double getx(){ return x;}double gety(){ return y;}};class Circle:public Point{private:double r;public:void set(double x1,double y1,double r1){Point::set(x1,y1);r=r1;}void print(){Point::print();cout<<r<<endl;}double getr(){ return r;}double s(){ return 3.14*r*r;}};void main(){Point p1;Circle c1;double x1,y1,r1;cin>>x1>>y1;p1.set (x1,y1);p1.print ();cin>>x1>>y1;p1.move (x1,y1);p1.print ();cin>>x1>>y1>>r1;c1.set (x1,y1,r1);c1.print ();cout<<c1.s()<<endl;}4、#include "iostream.h"class Point{private:int x,y;public:Point(){ }Point(int x1,int y1){ x=x1; y=y1;}friend Point operator+(Point &p1,Point &p2){Point p(p1.x+p2.x,p1.y+p2.y);return p;}void print(){cout<<"("<<x<<","<<y<<")"<<endl;}};void main(){Point p1(1,2),p2(2,3),p3;p3=p1+p2;p3.print();}5、#include "iostream.h"#include "stdio.h"#include "string.h"class Teacher{private:char name[20];public:void virtual input(){cout<<"input name:";cin>>name;}virtual double wage()=0;void virtual print(){cout<<name<<'\t';}};class Professor:public Teacher{private:int cnum; //课时数public:void input(){Teacher::input ();cout<<"input cnum:";cin>>cnum;}double wage(){return (3000+40*cnum);}void print(){Teacher::print ();cout<<wage()<<endl;}};class ViceProfessor:public Teacher {private:int cnum; //课时数public:void input(){Teacher::input ();cout<<"input cnum:";cin>>cnum;}double wage(){return (2500+30*cnum);}void print(){Teacher::print ();cout<<wage()<<endl;}};class Lecture:public Teacher{private:int cnum; //课时数public:void input(){Teacher::input ();cout<<"input cnum:";cin>>cnum;}double wage(){return (2000+25*cnum);}void print(){Teacher::print ();cout<<wage()<<endl;}};void main(){Teacher *t;Professor *p;ViceProfessor *vp;Lecture *l;char ptitle[20],ch;//职称do{cout<<"input ptitle(professor,viceprofessor or lecture):"<<endl;gets(ptitle);if(!strcmp(ptitle,"professor")){p=new Professor;t=p;}else if(!strcmp(ptitle,"viceprofessor")){vp=new ViceProfessor;t=vp;}else{l=new Lecture;t=l;}t->input ();t->print ();cout<<"continue(y/n)?";cin>>ch;}while(ch=='y');}。

《C语言程序设计（Visual C++6.0环境）》习题答案习题六一、思考题1、编写程序，将10个整形数2、4、6，…18，20赋给一个数组，然后使用指针输出显示该数组各元素的值。

#include “stdio.h”main(){int i,*p;int a[10]={2,4,6,8,10,12,14,16,18,20};p=a;for(i=0;i<10;i++)printf(“%3d”,*(p+i));}2、编写程序，将两个字符串连接起来。

#include<stdio.h>#define N 120main(){ char s1[N+N],s2[N],*p,*q;printf("输入2个字符串\n");scanf("%s%s",s1,s2);for(p=s1;* p!='\0'; p++);for(q=s2;*p++=*q++;);printf("两字符串连接后：%s\n",s1);}3、输入5个字符串，按英文字典排序从小到大顺序输出。

#include "stdio.h"#include "string.h"void sort(char *name[],int count){char *temp;int i,j,min;for(i=0;i<count-1;i++){min=i;for(j=i+1;j<count;j++)if(strcmp(name[min],name[j])>0)min=j;if(min!=i){temp=name[i];name[i]=name[min];name[min]=temp;}}}main(){char *name[5]={"BASIC","FORTRON","PASAL","C","FOXBASE"};int i=0;sort(name,5);for(;i<5;i++)printf("%s\n",name[i]);}4、编一程序，输入月份号，输出该月的英文月名。

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。