其他章節(jié)答案

/*The answer for Unit 4*/
/*
//Project 1
#include <stdio.h>
int main(void)
{
    char name[40],surname[40];
    printf("Please enter your name and surname.\n");
    scanf("%s%s",name,surname);
    printf("%s,%s\n",name,surname);
    return 0;
}
//Project 2
//這題不會(huì)
#include <stdio.h>
int main(void)
{
    printf("Please enter your name and surname.\n");
    scanf("%s%s",name,surname);
    printf("\"%s %s\"\n",name,surname);
}
//Project 3
#include <stdio.h>
int main(void)
{
    float f3;
    scanf("%f",&f3);
    printf("a.輸入%.1f或%.1e;\n",f3,f3);
    printf("b.輸入%+.3f或%.3E;\n",f3,f3);
    return 0;
}
//Project 4
#include <stdio.h>
int main(void)
{
    float height;
    char name[40];
    printf("Enter your height:_____cm\b\b\b\b\b\b\b");
    scanf("%f",&height);
    printf("Enter your name: ");
    scanf("%s",name);
    printf("%s,you are %.2f m tall\n",name,height/100.0);
    return 0;
}
//Project 5
#include <stdio.h>
int main(void)
{
    float spead,file,time;
    printf("Enter the spead of download:_____Mb/s\b\b\b\b\b\b\b\b\b");
    scanf("%f",&spead);
    printf("Enter the size of file:_____MB\b\b\b\b\b\b\b");
    scanf("%f",&file);
    time=file*8/spead;
    printf("At %.2f megabits per second, a file of %.2f megabytes\ndownloads in %.2f seconds.\n"
            ,spead,file,time);
    return 0;
}
*/
//Project 6
#include <stdio.h>
#include <string.h>
int main(void)
{
    char name[40],surname[40];
    int str1,str2; 
    printf("Enter your name: ");
    scanf("%s",name);
    printf("Enter your surname: ");
    scanf("%s",surname);
    printf("%s %s\n",name,surname);
    printf("%*d %*d\n",strlen(name),strlen(name),strlen(surname),strlen(surname));
    //In the book's 75 pages, it said that %zd is also applicable to strlen(),but in fact it doesn't apply.Use %d directly!
    printf("%s %s\n",name,surname);
    printf("%-*d %-*d\n",strlen(name),strlen(name),strlen(surname),strlen(surname));
    return 0;
}
//Project 7
#include <stdio.h>
#include <float.h>
//#define FLT_DIG 6
//#define DBL_DIG 15
//計(jì)算里存放浮點(diǎn)型數(shù)據(jù)硼讽，并不能精確表示宋渔。
//這兩個(gè)宏在float.h頭文件下面筷弦，用來說明double、float兩種數(shù)據(jù)類型有效數(shù)字的位數(shù)独悴，注意不是小數(shù)點(diǎn)后面的有效位數(shù)襟铭，而是所有位數(shù)系洛。
//#define DBL_DIG         15                      /* # of decimal digits of precision */
//#define FLT_DIG         6                       /* # of decimal digits of precision */
//float能保證的有效位數(shù)最多是6~7位噪漾，完全能保證的是6位，double是15~16位蜂莉，完全能保證的是15位蜡娶。
int main(void)
{
    double a = 1.0/3.0;
    float b = 1.0/3.0;
    printf("double values:%.6f,%.12f,%.16f;\nfloat values:%.6f,%.12f,%.16f;\n",a,b);
    printf("FLT_DIG:%d,\nDBL_DIG:%d\n",FLT_DIG,DBL_DIG);
    return 0;
 } 
//Project 8
#include <stdio.h> 
#define GL 3.785
#define YQ 1.609
int main(void)
    {
        float juli,jialun,haoyou1,haoyou2;
        printf("請(qǐng)輸入行駛里程（英里）:");
        scanf("%f",&juli); 
        printf("請(qǐng)輸入消耗汽油量（加侖）:");
        scanf("%f",&jialun);
        haoyou1 = jialun/juli;
        printf("燃料消耗:%.1f英里/加侖",haoyou1);
        haoyou2 = (jialun*3.785)/(juli*1.609/100);
        printf(" OR %.1f升/100公里\n",haoyou2);
        return 0;
    }