View Code of Problem 56

#include<stdio.h>
#include<math.h>
main()
{
	int a1,a2,b1,b2,c1,c2,a,b,c,h,min,s,n,m1,m2;
	scanf("%d:%d:%d",&a1,&b1,&c1);
	scanf("%d:%d:%d",&a2,&b2,&c2);
	m1=a1*3600+b1*60+c1;
	m2=a2*3600+b2*60+c2;
	n=fabs(m1-m2);
	h=n/3600;
	min=(n-h*3600)/60;
	s=(n-h*3600-min*60);
	printf("%2d:%02d:%02d",h,min,s);	//两位前如何添加0？%02d
}