经典c程序100例==91--100(1)

【程序91】
题目：时间函数举例1
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "time.h"
void main()
{ time_t lt; /*define a longint time varible*/
lt=time(NULL);/*system time and date*/
printf(ctime(<)); /*english format output*/
printf(asctime(localtime(<)));/*tranfer to tm*/
printf(asctime(gmtime(<))); /*tranfer to Greenwich time*/
}
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【程序92】
题目：时间函数举例2
1.程序分析：　　　　　　　　　　　
2.程序源代码：
/*calculate time*/
#include "time.h"
#include "stdio.h"
main()
{ time_t start,end;
int i;
start=time(NULL);
for(i=0;i<3000;i++)
{ printf("1111111111");}
end=time(NULL);
printf("1: The different is %6.3f",difftime(end,start));
}
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【程序93】
题目：时间函数举例3
1.程序分析：
2.程序源代码：
/*calculate time*/
#include "time.h"
#include "stdio.h"
main()
{ clock_t start,end;
int i;
double var;
start=clock();
for(i=0;i<10000;i++)
{ printf("1111111111");}
end=clock();
printf("1: The different is %6.3f",(double)(end-start));
}
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【程序94】
题目：时间函数举例4,一个猜数游戏，判断一个人反应快慢。（版主初学时编的）
1.程序分析：
2.程序源代码：
#include "time.h"
#include "stdlib.h"
#include "stdio.h"
main()
{char c;
clock_t start,end;
time_t a,b;
double var;
int i,guess;
srand(time(NULL));
printf("do you want to play it.('y' or 'n') ");
loop:
while((c=getchar())=='y')
{
i=rand()%100;
printf("please input number you guess:");
start=clock();
a=time(NULL);
scanf("%d",&guess);
while(guess!=i)
{if(guess>i)
{printf("please input a little smaller.");
scanf("%d",&guess);}
else
{printf("please input a little bigger.");
scanf("%d",&guess);}
}
end=clock();
b=time(NULL);
printf("1: It took you %6.3f seconds",var=(double)(end-start)/18.2);
printf("1: it took you %6.3f seconds",difftime(b,a));
if(var<15)
printf("11 You are very clever! 11");
else if(var<25)
printf("11 you are normal! 11");
else
printf("11 you are stupid! 11");
printf("11 Congradulations 11");
printf("The number you guess is %d",i);