1026 程序运行时间 (15 分)

#include <stdio.h>
#include <math.h>
#include <string.h>
int main()
{
	int c1,c2;
	scanf("%d %d",&c1,&c2);
					//int c=c2-c1;
	int c=round((c2-c1)/100.0);	//if(c%100>=50)c/=100,c++;
				 	//else c/=100;
	printf("%02d:%02d:%02d\n",c/3600,c%3600/60,c%60);
	return 0;
}