View Code of Problem 56

#include<stdio.h>

int swap(int *a,int *b){
	int temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

int main(){
	int h1,h2,m1,m2,s1,s2,h3,m3,s3;
	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){
		s3 = s1-s2;
	}else{
		s3 = s1+60-s2;
		m1--;
	}
	if(m1>m2){
		m3 = m1-m2;
	}else{
		m3 = m1-m2+60;
		h1--;
	}
	h3 = h1-h2;
	printf("%d:%02d:%02d",h3,m3,s3);
	return 0;
}