复习题

1~12

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编程练习

1. 打印姓名

/*4.8.1 -- 打印姓名*/
#include <stdio.h>
#include <stdlib.h>
#include<iostream>
using namespace std;
int main(void)
{
    char name[40];//名
    char surname[40];//姓
    cout<<"Please enter your name: ";
    cin>>name;
    cout<<"and enter your surname: ";
    cin>>surname;
    cout<<name<<","<<surname<<endl;

    system("pause");
    return 0;
}

2. 多格式打印名字

/*4.8.2 -- 多格式打印名字*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
using namespace std;
int main(void)
{
    char name[40];
    cout << "Please enter your name: ";
    cin >> name;
    printf("\"%s\"\n", name);
    printf("\"%20s\"\n", name);
    printf("\"%-20s\"\n", name);
    printf("%*s\n", strlen(name) + 3, name);

    system("pause");
    return 0;
}

3. 多格式打印浮点数

/*4.8.3 -- 多格式打印浮点数*/
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
int main(void)
{
    float number;
    cout << "Please input a number: ";
    cin >> number;

    printf("The input is %.1f or %.1e.\n", number, number);
    printf("The input is %+.3f or %.3E.\n", number, number);

    system("pause");
    return 0;
}

4. 打印身高和姓名

/*4.8.4 -- 打印身高和姓名*/
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
int main(void)
{
    float height;  //单位：英寸
    char name[40]; //姓名
    cout << "Please input your height: ";
    cin >> height;
    cout << "Please input your name: ";
    cin >> name;
    printf("%s, you are %.3f feet tall\n", name, height);

    system("pause");
    return 0;
}

5. 打印文件下载时间

/*4.8.5 -- 打印文件下载时间*/
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
int main(void)
{
    float speed;
    float file;
    cout << "Please input the download speed and the file size: ";
    cin >> speed >> file;

    printf("At %.2f megabits per second, a file of %.2f megabytes\ndownloads in %.2f seconds.\n", speed, file, file * 8 / speed);

    system("pause");
    return 0;
}

6. 打印姓名和字符长度

/*4.8.6 -- 打印姓名和字符长度*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
using namespace std;
int main(void)
{
    char name[40];    //名
    char surname[40]; //姓

    cout << "Please enter your name: ";
    cin >> name;
    cout << "and enter your surname: ";
    cin >> surname;

    printf("%s %s\n", name, surname);
    printf("%*d %*d\n", strlen(name), strlen(name), strlen(surname), strlen(surname));
    printf("%s %s\n", name, surname);
    printf("%-*d %-*d\n", strlen(name), strlen(name), strlen(surname), strlen(surname));
    system("pause");
    return 0;
}

7. 打印浮点数

/*4.8.7 -- 打印浮点数*/
#include <stdio.h>
#include <stdlib.h>
#include <float.h>
#include <iostream>
using namespace std;
int main(void)
{
    float n1 = 1.0 / 3.0;
    double n2 = 1.0 / 3.0;
    printf("n1: %.6f %.12f %.16f\n", n1, n1, n1);
    printf("n2: %.6f %.12f %.16f\n", n2, n2, n2);
    printf("FLT_DIG: %f\n",FLT_DIG);
    printf("DBL_DIG: %f\n",DBL_DIG);
    
    system("pause");
    return 0;
}

运行结果：
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8. 打印里程

/*4.8.8 -- 打印里程*/
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
#define gallonToLitre 3.785
#define mileToKm 1.609
int main(void)
{
    float mile;   //英里
    float gallon; //加仑
    cout << "Please input the miles and gallons: ";
    cin >> mile >> gallon;
    printf("%f gallon/mile = %.1f L/100km.\n", gallon / mile, gallon * gallonToLitre / (mile * mileToKm * 100));

    system("pause");
    return 0;
}