View Code of Problem 56

#include<iostream>
#include<algorithm>
#include<math.h>
using namespace std;
int main() {
	int h1,h2,m1,m2,s1,s2;
	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))
	{
		swap(h1,h2);
		swap(m1,m2);
		swap(s1,s2);
	}
	if(s1<s2)
	{
		m1--;
		s1=s1+60-s2;
	}
	else
	{
		s1=s1-s2;
	}
	if(m1<m2)
	{
		h1--;
		m1=m1+60-m2;
	}
	else
	{
		m1=m1-m2;
	}
	h1-=h2;
	printf("%d:%02d:%2d",h1,m1,s1);
	return 0;
}