HDU 1302 the snail 水一水

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1302

#include <iostream>
#include<cstdio>
#include <cstring>
#include<cmath>
#define maxn 50000 
using namespace std;

int main()
{
	int h,u,d,n;
	double f;
	while(scanf("%d",&h)&&h)
	{
		scanf("%d%d%lf",&u,&d,&f);
		int day=0;
		double ff=f/100;
		double sum=0;
		while(sum>=0&&sum<=h)
		{
			sum+=u-u*ff*day-d;
			day++;
		}
		if(sum<0) printf("failure on day %d\n",day);
		else if(sum>h) printf("success on day %d\n",day-1);
		               //最后爬出去是白天，所以最后那一天不算 
	} 
	return 0;
}