西安交大C++的作业答案

第一章1-2#include<iostream>using namespace std;int main(){double a,b,c;cout<<"请输入长:";cin>>a;cout<<"请输入宽:";cin>>b;cout<<"请输入高:";cin>>c;double s,v;s=a*b*2+b*c*2+a*c*2;v=a*b*c;cout<<"长方体的表面积s="<<s<<endl;cout<<"长方体的体积v="<<v<<endl;return 0;}1-7#include<iostream>#include<cmath>using namespace std;int main(){double n,y;cout<<"请输入n:";cin>>n;y=pow((1.0+1.0/n),n);cout<<"y="<<y<<endl;return 0;}1-8#include<iostream>#include<cmath>using namespace std;int main(){double x,y;cout<<"请输入一个大于0的数x:";cin>>x;y=sin(x)-log(x)+sqrt(x)-5;cout<<"y="<<y<<endl;return 0;}1-9#include<iostream>#include<cmath>using namespace std;int main(){double x,y;cout<<"请输入x:";cin>>x;if((x*x-3*x+2)<=0)return 1;else{y=x/(sqrt(x*x-3*x+2));cout<<"y="<<y<<endl;}return 0;}第二章2-2#include <iostream>using namespace std;int main(){double c,f;cout<<"请输入一个摄氏温度: "<<endl;cin>>c;f=9.0*c/5.0+32;cout<<"对应于的华氏温度为: "<<endl<<f<<endl;return 0;}2-3#include<iostream>#include<cmath>using namespace std;int main(){double x,y;cout<<"输入x:";cin>>x;y=sin(x*x)/(1-cos(x));cout<<"y="<<y<<endl;return 0;}2-5#include<iostream>#include<cmath>using namespace std;int main(){int m,n,k;double i,j;cout<<"请输入三个整数:";cin>>m>>n>>k;i=m+n+k;j=i/3;k=j+0.5;cout<<"和为:"<<i<<endl;cout<<"平均值为:"<<j<<endl;cout<<"平均值的四舍五入整数值:"<<k<<endl;return 0;}2-7#include <iostream>using namespace std;int main(){char ch;for(int i=0;i<3;i++){cout<<"请输入一个字母: "<<endl;cin>>ch;if(ch>='A'&&ch<='Z'){ch=ch-'A'+'a';cout<<"大小写转换后为: "<<endl<<ch<<endl;}else if(ch>='a'&&ch<='z'){ch=ch-'a'+'A';cout<<"大小写转换后为: "<<endl<<ch<<endl;}else{ch=ch;cout<<"大小写转换后为: "<<endl<<ch<<endl;}}return 0;}第三章3-4#include<iostream>#include<cmath>using namespace std;int main(){double y,u;int i=1,n;cout<<"请输入n:";cin>>n;if(n<0)cout<<"输入不合法"<<endl;else if(n=0){cout<<"y="<<1<<endl;}else{while(i<=n,i++)u=u*i;cout<<"y="<<u<<endl;}return 0;}3-5#include<iostream>using namespace std;int main(){int u=0;int i=1;int n;int k=1;cout<<"请输入n:";cin>>n;while(k<=n){u=u+i;i=i+2;k++;}cout<<"和为:"<<u<<endl;return 0;}3-10#include<iostream>#include<cmath>using namespace std;int main(){double u=0,k=1,i=1;int n;cout<<"请输入n:";cin>>n;while(i<=n){u=u+k;i=i+1;k=k*i;}cout<<"结果为:"<<u<<endl;return 0;}3-13#include<iostream>#include<cmath>using namespace std;int main(){int a,n,k,u=0,i=1,j=1;cout<<"请输入a,n:";cin>>a>>n;k=a;while(i<=n){u=u+k;k=k+10*j*a;j=j*10;i=i+1;}cout<<"结果为:"<<u<<endl;return 0;}第四章4-1#include <iostream>using namespace std;int main(){int M[4][4]={5,6,7,9,2,8,5,4,3,7,16,15,1,4,8,11,};int Mt[4][4];int i,j;for(i=0;i<4;i++)for(j=0;j<4;j++){Mt[i][j]=M[j][i];}cout<<"矩阵a的转置阵为："<<endl;for(i=0;i<4;i++){for(j=0;j<4;j++)cout<<Mt[i][j]<<"\t";cout<<endl;}return 0;}4-3#include <iostream>#include <cmath>using namespace std;int fac(int n){int result=1;while(n>1){result*=n;n=n-1;}return result;}int main(){int n;cout<<"请输入行数："<<endl;cin>>n;for(int l=0;l<n;l++){for(int m=0;m<=l;m++)cout<<fac(l)/(fac(m)*fac(l-m))<<"\t";cout<<endl;}return 0;}4-7#include <iostream>#include <cstring>using namespace std;char * my(char * string){char * ptr=string;while(*ptr!=0)ptr++;do{ptr--;}while(*ptr==' ');*(++ptr)=0;return string;}int main(){char str[100];cout<<"请输入一个末尾带空格的字符串"<<endl;cin.get(str,100);cout<<"截取前的原始字符串是:"<<endl<<"["<<str<<"]"<<endl;cout<<"截取空格后的字符串是:"<<endl;cout<<"["<<my(str)<<"]";cout<<endl;return 0;}4-8#include <iostream>#include <cstring>using namespace std;char *myltrim(char *string){char * ptr=string;while(*ptr==' ')ptr++;strcpy(string,ptr);return string;}int main(){char str[100];cout<<"请输入开头带空格的字符串"<<endl;cin.get(str,100);cout<<"截取前的原始字符串是:"<<endl<<"["<<str<<"]"<<endl;cout<<"截取空格后的字符串是:"<<endl;cout<<"["<<myltrim(str)<<"]";cout<<endl;return 0;}第五章5-2#include <iostream>using namespace std;int main(){char ch;for(int i=0;i<3;i++){cout<<"请输入一个字母: "<<endl;cin>>ch;if(ch>='A'&&ch<='Z'){ch=ch-'A'+'a';cout<<"大小写转换后为: "<<endl<<ch<<endl;}else if(ch>='a'&&ch<='z'){ch=ch-'a'+'A';cout<<"大小写转换后为: "<<endl<<ch<<endl;}else{ch=ch;cout<<"大小写转换后为: "<<endl<<ch<<endl;}}return 0;}5-4#include <iostream>int GCD(int x, int y);int LCM(int x, int y, int z);int main(void){using namespace std;cout << "请输入两个正整数：\n";int x;int y;cout << "第一个正整数：";cin >> x;cout << "第二个正整数：";cin >> y;int G_CD = GCD(x, y); // 最大公约数int L_CM = LCM(x, y, G_CD); // 最小公倍数= 两数乘积除以最大公约数cout << "最大公约数是：" << G_CD << endl;cout << "最小公倍数是：" << L_CM << endl;return 0;}int GCD(int x, int y){int z = x % y;while (z != 0){x = y;y = z;z = x % y;}return y;}int LCM(int x, int y, int z){return x * y / z;}5-5#include<iostream>#include<cmath>using namespace std;int mtk(int n){int r,s,t,q;r=n/100;s=n%10;t=n%100;q=t/10;t=r+s+q;return t;}int main(){for(int i=201;i<1000;i++){if(mtk(i)==5)cout<<i<<endl;}return 0;}5-9#include<iostream>#include<cmath>using namespace std;bool is_prime(int n){if(n<2)return false;for (int i=2;i*i<=n;i++){if(n % i == 0)return false;}return true;}int main(){int n;cout<<"请输入一个数n:";cin>>n;if (is_prime(n)){cout<<"该数是一个素数"<<endl;}else{cout<<"该数不是一个素数"<<endl;}return 0;}第六章6-5#include "stdio.h"int main(){int m;char*months[]={"January","February","March","April","May","June","July","August","September"," October","November","December"};printf("Input Month:");scanf("%d",&m);printf("The month is:%s",*(months+m-1));}6-6#include <iostream>using namespace std;int main(){char a[20];int i=0;cout<<"请输入一串字符:\n";cin>>a;for(;a[i];i++){if(a[i]>'a'&&a[i]<'z')a[i]-=32;else if(a[i]>'A'&&a[i]<'Z')a[i]+=32;}for(i=0;a[i];i++)cout<<a[i];cout<<endl;return 0;}6-7#include <iostream>using namespace std;int main(){char str[100];char *ptr=str;int total,capital,small,numeral,others;total=capital=small=numeral=others=0;cout<<"请输入字符串："<<endl;cin.get(ptr,100);while(*ptr!=0){total++;if(*ptr>='A'&&*ptr<='Z')capital++;else if(*ptr>='a'&&*ptr<='z')small++;else if(*ptr>='0'&&*ptr<='9')numeral++;else others++;ptr++;}cout<<"该字符串含有的大写字母个数："<<capital<<endl;cout<<"该字符串含有的数字字符个数："<<small<<endl;cout<<"该字符串含有的其它字符个数："<<numeral<<endl;cout<<"该字符串含有的其它字符个数："<<others<<endl;cout<<"该字符串总共含有的字符个数："<<total<<endl;return 0;}6-16#include <iostream>#include <cmath>using namespace std;double integral(double a,double b,double (*fun)(double),int n) {double h=(b-a)/n;double sum=((*fun)(a)+(*fun)(b))/2;int i;for(i=1;i<n;i++)sum+=(*fun)(a+i*h);sum*=h;return sum;}double yici(double r){double y=r;return y;}double erci(double s){double t=s*s;return t;double sanci(double u){double v=u*u*u;return v;}int main(){double a=0,b=1;cout<<"sin(x)结果是"<<integral(a,b,sin,1000)<<endl;cout<<"x结果是"<<integral(a,b,erci,1000)<<endl;cout<<"x*x结果是"<<integral(a,b,yici,1000)<<endl;cout<<"x*x*x结果是"<<integral(a,b,sanci,1000)<<endl;cout<<"exp(x)结果是"<<integral(a,b,exp,1000)<<endl;return 0;}第七章7-1#include <iostream>#include <cstring>using namespace std;class Dog{char name[20];int age;char sex;float weight;public:void Register(char * Name,int Age,char Sex,float Weight);char * GetName(){return name;}int GetAge(){return age;}char GetSex(){return sex;}float GetWeight(){return weight;}void Speak(){cout<<"Arf!Arf!"<<endl;}};void Dog::Register(char * Name,int Age,char Sex,float Weight) {strcpy(name,Name);age=Age;sex=Sex;weight=Weight;int main(){char name[20],sex;int age;float weight;Dog dog1;cout<<"Please input name, age, sex and weight"<<endl;cin>>name>>age>>sex>>weight;dog1.Register(name,age,sex,weight);cout<<"Dog’s name:"<<dog1.GetName()<<endl;cout<<"Dog’s age:"<<dog1.GetAge()<<endl;cout<<"Dog’s sex:"<<dog1.GetSex()<<endl;cout<<"Dog’s weight:"<<dog1.GetWeight()<<endl;cout<<"Dog speak:";dog1.Speak();return 0;}7-2#include <iostream>using namespace std;const double pi=3.14;class Circle{public:void set();void show();double circumference();double area();private:int x,y;double r;};void Circle::set(){cout<<"请输入圆心坐标和圆的半径"<<endl;cin>>x;cin>>y;cin>>r;}void Circle::show()cout<<"该圆为"<<endl;cout<<"圆心("<<x<<","<<y<<")"<<endl;cout<<"半径"<<r<<endl;}double Circle::circumference(){return 2*pi*r;}double Circle::area(){return pi*r*r;}int main(){Circle c;c.set();c.show();cout<<"圆的周长为"<<c.circumference()<<endl;cout<<"圆的面积为"<<c.area()<<endl;return 0;}7-4#include <iostream>using namespace std;class Address{char Name[30];char StreetAddress[30];char City[30];char Postcode[30];public:Address(char*a,char*b,char*c,char*d){strcpy(Name,a);strcpy(StreetAddress,b);strcpy(City,c);strcpy(Postcode,d);void Changename(char*a){strcpy(Name,a);}void Display(){cout<<Name<<"address:"<<endl;cout<<Postcode<<" "<<City<<" "<<StreetAddress<<endl;}};int main(){char name[30];char streetaddress[30];char city[30];char postcode[30];cin>>name>>streetaddress>>city>>postcode;Address x(name,streetaddress,city,postcode);x.Display();cin>>name;x.Changename(name);x.Display();return 0;}7-5class Point3D{double x,y,z;public:point3D(double _x,double _y,double _z) {x=_x; y=_y; z=_z;}~Point3D(){ }double Distance(Point3D &p) {double a=p.x; double b=p.y; double c=p.z;return sqrt((x-a)*(x-a)+(y-b)*(y-b)+(z-c)*(z-c));}};int main(){double x,y,z,a,b,c;cin>>x>>y>>z>>a>>b>>c;Point3D point1(x,y,z);Point3D point2(a,b,c);cout<<point1.Distance(point2)<<endl;return 0;}第八章8-1#include <iostream>using namespace std;class Point{public:int x, y;Point( int a= 0, int b= 0 ){x=a;y=b;}};class ColorPoint : public Point{int r, g, b;public:ColorPoint(int a,int bb,int c,int d,int e):Point(a,bb){r=c;g=d;b=e; }void Print() {cout<<"[x,y]="<<x<<","<<y<<endl;cout<<"r*256*256+g*256+b="<<r*256*256+g*256+b<<endl;}};int main(){int a,b,c,d,e; cin>>a>>b>>c>>d>>e;ColorPoint x(a,b,c,d,e); x.Print();return 0;}8-2class Person{string ID; //身份证号string Name; //姓名string Sex; //性别int Age; //年龄public:Person(string id, string name, string sex, int age) {ID= id;Name= name;Sex= sex;Age= age;}virtual void display(){cout<<"身份证号："<<ID<<endl;cout<<"姓名："<<Name<<endl;cout<<"性别："<<Sex<<endl;cout<<"年龄："<<Age<<endl;}};class teacher:public Person{string Major; //专业string Title; //职称string Course; //主讲课程public:teacher(string id, string name, string sex, int age, string major, string title, string course):Person(id,name,sex,age){Major=major;Title=title;Course=course;}virtual void display(){Person::display();cout<<"专业："<<Major<<endl;cout<<"职称："<<Title<<endl;cout<<"主讲课程："<<Course<<endl;}};int main(){string id,name,sex,major,title,course;int age;cin>>id>>name>>sex>>age>>major>>title>>course;teacher x(id,name,sex,age,major,title,course);x.display();return 0;}8-3class truck:public vehicle{double Passenger_load; //载人数double Payload; //载重量public:truck(double wheels, double weight, double passenger_load, double payload):vehicle(wheels,weight) {Passenger_load=passenger_load; Payload=payload;}virtual void Display() {vehicle::Display();cout<<"载人数："<<Passenger_load<<endl;cout<<"载重量："<<Payload<<endl;}};int main(){double wheels1, weight1, passenger_load1;double wheels2, weight2, passenger_load2, payload;cout<<"输入小车参数"<<endl;cin>>wheels1>>weight1>>passenger_load1;car c(wheels1, weight1, passenger_load1);c.Display();cout<<"输入卡车参数"<<endl;cin>>wheels2>>weight2>>passenger_load2>>payload;truck t(wheels2, weight2, passenger_load2, payload);t.Display();return 0;}8-6class Ellispe{double x, y; //圆心坐标double semi_major_axis; //半长轴double semi_minor_axis; //半短轴public:Ellispe(double X, double Y, double Semi_major_axis, double Semi_minor_axis){x=X;y=Y;semi_major_axis=Semi_major_axis;semi_minor_axis=Semi_minor_axis;}void Display(){cout<<"圆心坐标为"<<x<<" "<<y<<endl;cout<<"面积为"<<area()<<endl;}double area(){return pi*semi_major_axis*semi_minor_axis;}};int main(){double x, y, semi_major_axis, semi_minor_axis;double areas;cin>>x>>y>>semi_major_axis>>semi_minor_axis;Ellispe e(x, y, semi_major_axis, semi_minor_axis);e.Display();return 0;}第九章9-1class Mammal{public:virtual void Speak(){cout<<"I am a mammal."<<endl;}};class Dog:public Mammal{public:virtual void Speak(){cout<<"I am a dog."<<endl;}};int main(){Mammal ma1,*p;Dog dog1;p=&ma1;p->Speak();p=&dog1;p->Speak();return 0;}9-3class Motor{protected:int number_person;int number_tyre;int horsepower;char manufacturers[30];char owner[30];public:Motor(int _number_person,int _number_tyre,int _horsepower,char *_manufacturers,char *_owner) {number_person=_number_person;number_tyre=_number_tyre;horsepower=_horsepower;strcpy(manufacturers,_manufacturers);strcpy(owner,_owner);}virtual void Display() {cout<<"number_person:"<<number_person<<endl;cout<<"number_tyre:"<<number_tyre<<endl;cout<<"horsepower:"<<horsepower<<endl;cout<<"manufacturers:"<<manufacturers<<endl;cout<<"owner:"<<owner<<endl;}};class Car:public Motor{public:Car(int _number_person,int _number_tyre,int _horsepower,char *_manufacturers,char *_owner):Motor(_number_person, _number_tyre, _horsepower,_manufacturers,_owner) {}void Display() {cout<<"I am a Car"<<endl;Motor::Display();}};class Bus:public Motor{ int number;public:Bus(int _number_person,int _number_tyre,int _horsepower,char *_manufacturers,char *_owner,int _number) :Motor(_number_person, _number_tyre, _horsepower,_manufacturers,_owner) {number=_number;}void Display() {cout<<"I am a Bus"<<endl;Motor::Display();cout<<"number:"<<number<<endl;}};class Bus:public Motor{ int number;public:Bus(int _number_person,int _number_tyre,int _horsepower,char *_manufacturers,char *_owner,int _number) :Motor(_number_person, _number_tyre, _horsepower,_manufacturers,_owner) {number=_number;}void Display() {cout<<"I am a Bus"<<endl;Motor::Display();cout<<"number:"<<number<<endl;}};class Truck:public Motor{int weight;public:Truck(int _number_person,int _number_tyre,int _horsepower,char *_manufacturers,char *_owner,int _weight) :Motor(_number_person, _number_tyre, _horsepower,_manufacturers,_owner) {weight=_weight;}void Display() {cout<<"I am a Truck"<<endl;Motor::Display();cout<<"weight:"<<weight<<endl;}};int main(){Motor *p;int number_person,number_tyre,horsepower,number,weight;char manufacturers[30];char owner[30];cin>>number_person>>number_tyre>>horsepower>>manufacturers>>owner;Car car(number_person,number_tyre,horsepower,manufacturers,owner);p=&car;p->Display();cin>>number;Bus bus(number_person,number_tyre,horsepower,manufacturers,owner,number);p=&bus;p->Display();cin>>weight;Truck truck(number_person,number_tyre,horsepower,manufacturers,owner,weight);p=&truck;p->Display();return 0;}9-4#include<iostream>#include<cmath>using namespace std;const double PI=3.1415926;class Shape{public:virtual double CalculateArea()=0;virtual double CalculatePerim()=0;virtual void Display() {cout<<"Area:"<<CalculateArea()<<endl;cout<<"Perim:"<<CalculatePerim()<<endl;}};class Square:public Shape{double edge;public:Square(double _edge) {edge=_edge;}virtual double CalculateArea() { return edge*edge;}virtual double CalculatePerim() {return 4*edge;}void Display() {cout<<"I am a Square"<<endl;Shape::Display();}};class Circle:public Shape{double radius;public:Circle(double _radius) {radius=_radius; }virtual double CalculatePerim() {return 2*radius*PI; }virtual double CalculateArea(){return radius*radius*PI;}void Display() {cout<<"I am a Circle"<<endl;Shape::Display();}};class Trapezoid:public Shape{double height; double up; double down;public:Trapezoid(double _up,double _down,double _height) { up=_up; down=_down; height=_height;}virtual double CalculatePerim() {double temp; //腰长temp=sqrt((down-up)*(down-up)/4+height*height);return temp*2+down+up;}virtual double CalculateArea() {return (up+down)*height/2;}void Display() {cout<<"I am a Trapezoid"<<endl;Shape::Display();}};第十章10-1#include <iostream>#include <iomanip>#include <cmath>using namespace std;int main(){ double a = 3.1415926;int places;for ( places = 1; places <= 8; places++ ){double b=4.5/pow(10.0,places);cout.precision( places );cout << a-b << '\n';}return 0;}10-2#include <iostream>#include <fstream>#include <iomanip>using namespace std;int main(){char ch;int line=1;ifstream in("01.cpp");if(! in){cout<<"不能读入文件"<<endl;return 1;}cout<<setw(4)<<line<<"";while (in){in.get(ch);if(in)cout<<ch;if (ch=='\n'){line++;cout<<setw(4)<<line<<"";}}in.close();return 0;}10-3#include <iostream>#include <string>#include <fstream>#include <iomanip>using namespace std;int main(){char ch;int n=1;ifstream fin("11.txt");if (!fin){cout<<"打开失败"<<endl;return 1;}int a[10];int i=0;a[i]=0;while(fin){fin.get(ch);if(ch!='\n')a[i]++;if(ch=='\n'){i++;n++;a[i]=0;}cout<<ch;}cout<<endl;for (i=0;i<n;i++){for (int j=i;j<n;j++){if(a[j]<a[i]){int tmp=a[i];a[i]=a[j];a[j]=tmp;}}}cout<<"最长的一行的字符的个数:"<<a[0]<<endl;cout<<"最长的一行的字符的个数:"<<a[n-1]<<endl;fin.close();return 0;}10-4#include <iostream>#include <string>#include <fstream>#include <iomanip>using namespace std;class employee{public:char num[20];char name[10];char place[10];int age;employee(){ }employee(char *num, char *name,char *place,int Age){strcpy(this->name,name);strcpy(this->num,num);strcpy(this->place,place);age=Age;}void showme (){cout << num<< " " << name<<" "<<place<<" "<<age<< endl;} };int main(){employee emp[6]={employee("001011","张三","北京",20),employee("001012","李四","上海",23),employee("001013","王丽","广州",21),employee("001014","王刚","陕西",18),employee("001015","Kimi","台湾",25),employee("001016","Cindy","陕西",20)};ofstream file1("file.dat");if (!file1){cout<<"打开失败"<<endl;return 1;}for (int i=0;i<6;i++)file1.write((char *)&emp[i],sizeof(emp[i]));file1.close();employee emp2;ifstream file2("file.dat");ifstream file3("file.dat");if (!file2){cout<<"打开失败"<<endl;return 1;}double sum=0,n=0;while (file2){file2.read((char *)&emp2,sizeof(emp2));if (file2){if(emp2.age<22){emp2.showme();n++;sum=sum+emp2.age;}}}double average=1.0*sum/n;cout.precision(2);cout<<"小于22岁的人的平均年龄:"<<average<<endl;cout<<"籍贯是上海的人如下："<<endl;int m=0;if (!file3){cout<<"打开失败"<<endl;return 1;}while (file3){file3.read((char *)&emp2,sizeof(emp2));if (file3){if(strcmp(emp2.place,"上海")==0){emp2.showme();m++;}}}cout<<"籍贯是上海的人数:"<<m<<endl;file2.close();return 0;}。