请教一个简单程序的性能问题

#include<stdio.h>
int Difference(int a, int b,int c);

/*function main begins*/
int main(void)
{
 int x,y,z;

 printf(“enter the hour :\n”);
 scanf(“%d”,&x);

 
 printf(“enter the Minutes:\n”);
 scanf(“%d”,&y);
 
 printf(“enter the seconds:\n”);
 scanf(“%d”,&z);
 
 while(x<0||x>=12||y<0||y>=60||z<0||z>=60){
 printf(“time is illeag,Please input again\n”);
 scanf(“%d%d%d\n”,&x,&y,&z);
 }

 Difference(x,y,z);

 return 0;
}

int Difference(int a, int b, int c)
{
 int total;
 total= a*60*60+b*60+c;
 
 printf(“total time is %d\n”,total);

 return total;
}

 

我运行上面这个程序的时候,电脑cpu利用率将近达到100%,把while循环去掉之后就快了很多.while语句不会这么影响性能吧.