hdoj 时钟 2180 （数学）

时钟

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1732    Accepted Submission(s): 438

Problem Description

从a点b分到s点t分时针和分针重合多少次?

Input

有多组数据，每组1行4个数 a,b,s,t. 1<=a,s <=12, 0<=b,t<60. 0 0 0 0结束.

Output

参看Sample output

Sample Input

12 50 1 2 
3 8 3 20 
2 45 11 0 
11 0 3 20 
1 2 12 50 
3 20 3 8
0 0 0 0

Sample Output

0
1
8
4
11
10

#include<stdio.h>
int main()
{
	int a,b,aa,bb;
	while(scanf("%d%d%d%d",&a,&b,&aa,&bb),a|b|aa|bb)
	{
		a%=12;
		aa%=12;
		int x=(a*60+b)*11;
		int y=(aa*60+bb)*11;
		if(y<x)
			y+=720*11;
		int cnt=y/720-x/720;
		if(x==0)
			cnt++;
		printf("%d\n",cnt);
	}
	return 0;
}