http://acm.hdu.edu.cn/showproblem.php?pid=5112


排序之后计算就好 开始用cin超时了


#include<stdio.h>
#include<iostream>
#include<math.h>
#include<stdlib.h>
#include<ctype.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<queue>
#include<stack>
#include<set>
#include<map>
#include<sstream>
#include<time.h>
#include<utility>
#include<malloc.h>
#include<stdexcept>

using namespace std;

struct q
{
	int t ;
	int dis;
}p[10005];

int t ;
int n;

bool cmp (q a,q b)
{
	return a.t < b.t;
}

int k=1;

int main()
{
    scanf("%d",&t);
	while (t--)
	{
		scanf("%d",&n);
		for(int i=1;i<=n;i++)
			scanf("%d %d",&p[i].t,&p[i].dis);
		sort(p+1,p+1+n,cmp);

		double ans = (p[2].dis - p[1].dis) * 1.0 / ( p[2].t - p[1].t);

		for(int i=3;i<=n;i++)
		{
			ans = max (ans ,double ( abs( (p[i].dis-p[i-1].dis) )*1.0 / (p[i].t - p[i-1].t) ) );
		}
		printf("Case #%d: %.2lf\n",k++,ans);
	}
    return 0;
}