C++ Primer Plus 中文第六版 第五章编程练习答案

/*个人练习，如有错误敬请指正*/

#include <iostream>
#include <string>
#include <cstring>
#include<ctime>
#include <array>

using namespace std;

void p5t1()
{
    int a,b,count=0;
    cout<<"INPUT TWO NUMBER: LIKE 9 10"<<endl;
    cin>>a;
    cin>>b;
    for(int i=a;i<=b;i++)
    {
        count+=i;
    }
    cout<<"SUM:"<<count<<endl;
}

void p5t2()
{
    array<long double,101> a{};
    a[0]=a[1]=1;
    for(int i=2;i<101;i++)
    {
        a[i]=i*a[i-1];
    }
    for(int i=0;i<101;i++)
    {
        cout<<i<<"!="<<a[i]<<endl;
    }
}

void p5t3()
{
    int current=0;
    int sum=0;
    while(true) {
        cout << "INPUT A NUMBER" << endl;
        cin >> current;
        sum += current;
        cout << "SUM:" << sum<<endl;
        if(current==0)
            break;
    }
}

void p5t4()
{
    double D=100;
    double C=100;
    int year=0;
    while(D>=C)
    {
        D+=10;
        C*=1.05;
        year++;
    }
    cout<<"YEAR:"<<year<<endl;
    cout<<"D:"<<D<<"  C:"<<C<<endl;
}

void p5t5()
{
    string months[12] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    int grades[12];
    int sum=0;
    for(int i=0;i<12;i++)
    {
        cout<<months[i]<<" INPUT SCALES: "<<endl;
        cin>>grades[i];
    }
    for(int grade : grades)
    {
        sum+=grade;
    }
    cout<<"SUM OF:"<<sum<<endl;
}

void p5t6()
{
    string months[12] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    int grades[3][12];
    int s[3]={0};
    for(int i=0;i<3;i++)
    {
        cout<<"THE "<<i+1<<"YEAR"<<endl;
        for(int j=0;j<12;j++)
        {
            cout<<months[j]<<" INPUT SCALES: "<<endl;
            cin>>grades[i][j];
            s[i]+=grades[i][j];
        }
    }
    for(int i=0;i<3;i++)
    {
        cout<<"THE "<<i+1<<"YEAR"<<s[i]<<endl;
    }
    cout<<"TOTAL SUM:"<<s[0]+s[1]+s[2]<<endl;
}

typedef struct car
{
   string factory;
   int year;
}c;

void p5t7()
{
    int carnum=0;
    cout<<"How many cars do you wish to catalog?"<<endl;
    cin>>carnum;
    c *par=new c[carnum];
    for(int i=0;i<carnum;i++)
    {
        cout<<"Car #"<<i+1<<":\n";
        cin.get();
        cout<<"Please enter the make:";
        getline(cin,par[i].factory);
        cout<<"Please enter the year made:";
        cin>>par[i].year;
    }
    cout<<"Here is your collection:"<<endl;
    for(int i=0;i<carnum;i++)
    {
        cout<<par[i].factory<<" "<<par[i].year<<endl;
    }
}

void p5t8()
{
    char input[128];
    int num=0;
    cout<<"Enter words (to stop, type the word done):"<<endl;
    while(cin>>input)
    {
        if(strcmp(input,"done") != 0)
            num++;
        else
            break;
    }
    cout<<"You entered a total of "<<num<<"words"<<endl;

}

void p5t9()
{
    string input;
    int num=0;
    cout<<"Enter words (to stop, type the word done):"<<endl;
    while(cin>>input)
    {
        if(input!="done")
            num++;
        else
            break;
    }
    cout<<"You entered a total of "<<num<<" words"<<endl;

}

void p5t10()
{
    int num=0;
    cout<<"Enter number of rows:";
    cin>>num;
    for(int i=0;i<num;i++)
    {
        for(int j=0;j<num-i-1;j++)
        {
            cout<<".";
        }
        for(int k=num-i-1;k<num;k++)
        {
            cout<<"*";
        }
        cout<<"\n";
    }


}

int main()
{
    while(1) {
        int num;
        cout << "\n输入要做的题号" << endl;
        cin >> num;
        if (num == 1)
            p5t1();
        else if(num==2)
            p5t2();
        else if(num==3)
            p5t3();
        else if(num==4)
            p5t4();
        else if(num==5)
            p5t5();
        else if(num==6)
            p5t6();
        else if(num==7)
            p5t7();
        else if(num==8)
            p5t8();
        else if(num==9)
            p5t9();
        else if(num==10)
            p5t10();
        else
            break;
    }