一个猜数游戏，判断一个人反应快慢

#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') /n");
loop:
while((c=getchar())=='y')
{
i=rand()%100;
printf("/nplease input number you guess:/n");
start=clock();
a=time(NULL);
scanf("%d",&guess);
while(guess!=i)
{if(guess>i)
{printf("please input a little smaller./n");
scanf("%d",&guess);}
else
{printf("please input a little bigger./n");
scanf("%d",&guess);}
}
end=clock();
b=time(NULL);
printf("/1: It took you %6.3f seconds/n",var=(double)(end-start)/18.2);
printf("/1: it took you %6.3f seconds/n/n",difftime(b,a));
if(var<15)
printf("/1/1 You are very clever! /1/1/n/n");
else if(var<25)
printf("/1/1 you are normal! /1/1/n/n");
else
printf("/1/1 you are stupid! /1/1/n/n");
printf("/1/1 Congradulations /1/1/n/n");
printf("The number you guess is %d",i);
}
printf("/ndo you want to try it again?(/"yy/".or./"n/")/n");
if((c=getch())=='y')
goto loop;
}