c ++ primer plus Chapter Programming Exercises

Chapter V circulation and relational expressions

Q8 reference to someone else's blog O (∩_∩) O

//第一题
# include<iostream>
int main()
{
    using namespace std;
    int small;
    int big;
    int sum = 0;
    cout<<"please input the smaller number:"<<endl;
    cin>>small;
    cout<<"please input the bigger number:"<<endl;
    cin>>big;
    for(int i = small;i<=big;++i)
        sum += i;
    cout<<"sum = "<<sum;
    return 0;
}

```cpp
//第二题 用array
# include<iostream>
# include<array>//使用array别忘了include
using namespace std;
const int artsize = 16;
int main()
{
    array<long long, artsize> factor;//arrar<type,num> a1，array是动态数组的替代
    factor[0] = 1;                   //顺便再记一下vector<type>a1(num)，vector是定长数组的替代
    factor[1] = 1;
    for (int i = 2;i<artsize;++i)
        factor[i] = i*factor[i-1];
    for(int i = 0;i<artsize;i++)
        cout<<i<<"!= "<<factor[i]<<endl;
    return 0;
}

```cpp
//第二题 用long double
# include<iostream>
using namespace std;
const int artsize = 16;
int main()
{
    cout.setf(ios_base::fixed,ios_base::floatfield);//为了了解精度，防止把较大的数转化为E表示法，使程序显示到小数点后6位
    long double factor[artsize];
    factor[0] = 1;
    factor[1] = 1;
    for(int i =2;i<artsize;++i)
        factor[i] = i*factor[i-1];
    for(int i = 0;i<artsize;++i)
        cout<<i<<"!= "<<factor[i]<<endl;
    return 0;
}

//第三题
# include<iostream>
using namespace std;
int main()
{
    int num;
    int sum;
    cout<<"input 0 to quit,please input numbers:";
    cin>>num;
    while(num!=0)
    {
        sum+=num;
        cout<<sum<<endl;
        cin>>num;
    }
}

//第四题
# include<iostream>
using namespace std;
int main()
{
    const double daph_rate = 0.1;
    const double cleo_rate = 0.05;
    const double ori_money = 100;
    double daph = ori_money+daph_rate*ori_money;
    double cleo = ori_money+cleo_rate*ori_money;
    int i;
    for(i = 1;daph>=cleo;++i)
    {
        daph += daph_rate*ori_money;
        cleo += cleo*cleo_rate;
    }
    cout<<"第"<<i<<"年 cleo 的存款超过 daph"<<endl;
    cout<<"daph的存款为："<<daph<<"$"<<endl;
    cout<<"cleo的存款为："<<cleo<<"$"<<endl;
    return 0;
}

//第五题
# include<iostream>
# include<string>
using namespace std;
int main()
{
    long sum = 0;
    string month[12]={"January","February","March", "April", "May", "June", "July",
                      "August", "September","October","November", "December"};
//将从键盘输入的数据存入int数组中
    int mon[12];
    for(int i = 0;i<=11;++i)
    {
        cout<<"please input "<<month[i]<<"卖出多少册书"<<":"<<endl;
        cin>>mon[i];
    }
    for(int j = 0;j<=11;++j)
    {
        sum+=mon[j];
    }
    for(int k = 0;k<=11;++k)
        cout<<month[k]<<"卖出"<<mon[k]<<"册书"<<endl;
    cout<<"全年卖出"<<sum<<"册书";
    return 0;

}

// 第六题 记录三年每个月的销售量构造二维数组
# include<iostream>

const int m = 3;
const int n = 12;
int main()
{
    using namespace std;
    //将指针数组初始化为字符串常量
    const char * month[n] =
            {
            "January","February","March","April","May   ",
            "June   ","July   ","August","September","October",
            "November","December"
    };
    int num[m][n];
    long sum=0;
    long sum_year = 0;
    cout<<"the numbers of sold books:2018-2020\n\n";
    for(int p=0;p<m;++p)
    {
        int i;
        for (i = 0;i<n;++i)
        {
            cout<<"请输入"<<2018+p<<"年"<<month[i]<<"的销售量"<<endl;
            cin>>num[p][i];
            sum+=num[p][i];
        }

    }
    for(int j = 0;j<n;++j)
    {
        cout<<month[j]<<":   \t";
        for (int k = 0; k<m; ++k)
        {
            cout<<num[k][j]<<"\t";
        }
        cout<<endl;
    }
    cout<<"三年的总销售量为："<<sum;
    return 0;
}

//第七题 用new 创建动态数组
# include<iostream>
# include<string>
using namespace std;
struct car{
    string make;
    int year;
};
int main()
{
    int size;
    cout<<"how many cars do you want to catalog?";
    cin>>size;
    car *point = new car[size] ;//用new分配的内存没有名字，只能通过指针访问。
    for (int i=0;i<size;++i)
    {
        cout<<"Car #"<<i+1<<endl;
        cout<<"please enter the make:";
        cin.get();
        getline(cin, point[i].make);
        cout<<"please enter the year made:";
        cin>>point[i].year;
    }
    cout<<"here is your collection:"<<endl;
    for (int j=0;j<size;++j)
    {
        cout<<point[j].year<<" "<<point[j].make<<endl;
    }
    return 0;
}

//第八题
// https://blog.csdn.net/wyl1813240346/article/details/80361734
#include<iostream>
# include<cstring>
using namespace std;
int main()
{
    cout<<"Enter words(to stop enter the word done):"<<endl;
    int count = 0;
    char ch[20];
    while(cin>>ch&&strcmp(ch,"done"))
        ++count;
    cout<<count<<endl;
    return 0;
}

//第九题 用string对象
# include<iostream>
# include<string>
using namespace std;
int main()
{
    int count = 0;
    string word;
    cout<<"please input a text:"<<endl;
        while(cin>>word&&word!="done")
            ++count;

    cout<<count;
    return 0;
}

//第十题
# include<iostream>
using namespace std;
int main()
{
    cout<<"enter number of rows:";
    int n;
    cin>>n;
    for (int i = 1;i<=n;++i)
    {
        for (int j = 1;j<=n-i;++j)
            cout<<".";
        for (int k = 1;k<=i;++k)
            cout<<"*";

        cout<<"\n";
    }
    return 0;
}