【C Primer Plus】編程練習第四章

一、

#include <stdio.h>

int main()
{
    char a[10] = { 0 };
    char b[10] = { 0 };
    printf("請輸入您的姓名：");
    scanf("%s,%s", a, b);
    getchar();
    printf("歡迎您%s,%s",a, b);
    getchar();
    return 0;
}

 

二、

#include <stdio.h>
#include <string>
int main()
{
    char a[100] = { 0 };
    printf("請輸入您的姓名：");
    scanf("%s",a);
    getchar();
    int len = strlen(a);
    printf("%d\n", len);
    printf("\"%s\"\n",a);
    printf("\"%20s\"\n", a);
    printf("\"%-20s\"\n", a);
    printf("\"%*s\"",len+3, a); //若是後面只有一個參數，*沒有意義，若是有兩個參數，*表明打印數據長度，本句至關於 printf("\"%10s\"",a)
    getchar();
    return 0;
}

 

 三、

#include <stdio.h>
#include <string>
int main()
{
    float f=0;
    printf("請輸入一個浮點數：");
    scanf("%f",&f);
    getchar();
    printf("The input is %0.1f or %0.1e", f, f);
    
    getchar();
    return 0;
}

 

 四、

#include <stdio.h>
#include <string>
int main()
{
    char name[20] = { 0 };
    float f=0;
    printf("請輸入你的姓名和身高：");
    scanf("%s %f", name,&f); //這裏要注意若是採用逗號來分隔的話，會致使&f並不會接收到數據，只有空格才能表示字符串輸入結束
    getchar();
    printf("%s,you are %f feet tall", name,f);
    getchar();
    return 0;
}

 

 五、

#include <stdio.h>
#include <string>
int main()
{
    float speed, file,time,speeds;
    printf("請輸入下載速度和文件大小：");
    scanf("%f,%f", &speed, &file);
    getchar();
    speeds = speed / 8;  //題中給出的爲bit，要化爲byte
    time = file / speeds;
    printf("At %0.2f megabits per second,a file of %0.2f megabytes\n",speed,file);
    printf("downloads in %0.2f seconds", time);
    getchar();
    return 0;
}

 

 

 六、

#include <stdio.h>
#include <string>
int main()
{
    char xin[10] = { 0 };
    char min[10] = { 0 };
    printf("請輸入您的名：");
    scanf("%s", min);
    getchar();
    printf("請輸入您的姓：");
    scanf("%s", xin);
    getchar();
    int len_x, len_m;
    len_x = strlen(xin);
    len_m = strlen(min);
    printf("%s,%s\n", min, xin);
    printf("%*d,%*d\n", len_m, len_m, len_x, len_x);
    printf("%s,%s\n", min, xin);
    printf("%-*d,%-*d", len_m, len_m, len_x, len_x);
    getchar();
    return 0;
}

 

 七、

#include <stdio.h>
#include <string>
int main()
{
    double a = 1.0 / 3.0;
    float b = 1.0 / 3.0;
    printf("%0.6lf,%0.6lf\n", a, b);
    printf("%0.12lf,%0.12lf\n", a, b);
    printf("%0.18lf,%0.18lf\n", a, b);
    printf("%d,%d\n", FLT_DIG, DBL_DIG);  //這兩個宏在float.h頭文件下面，用來講明double、float兩種數據類型有效數字的位數，注意不是小數點後面的有效位數，而是全部位數。
    getchar();
    return 0;
}

 

 八、

#include <stdio.h>
#include <string>
#define GALLON 3.785
#define MILE 1.609*100
int main()
{
    float gallon = 0;
    float mile = 0;
    double gal_mil = 0;
    double l_m=0;
    printf("請輸入里程和耗油量：");
    scanf("%f,%f", &mile, &gallon);
    getchar();
    gal_mil = mile / gallon;
    printf("消耗每加侖行駛英里數爲：%0.1lf\n", gal_mil);
    l_m = (gallon*GALLON) / (MILE*mile);
    printf("把它化爲升每一百千米：%0.1lf", l_m);
    getchar();
    return 0;
}