View Code of Problem 56

#include<stdio.h>
main()
{
	int h1,m1,s1,h2,m2,s2;
	int h,m,s;
	scanf("%d:%d:%d",&h1,&m1,&s1);
	scanf("%d:%d:%d",&h2,&m2,&s2);
	if(h1>h2||(h1<=h2&&m1>m2)||(h1<=h2&&m1<=m2&&s1>s2))
		printf("ERROR!\n");
	else
	{
		if(s2>=s1)s=s2-s1;
		else
		{
			s=s2+60-s1;
			m2-=1;
		}
		if(m2>=m1)m=m2-m1;
		else
		{
			m=m2+60-m1;
			h2-=1;
		}
		h=h2-h1;
		printf("%d:%02d:%02d\n",h,m,s);
	}
}