poj 3301 Texas Trip

http://poj.org/problem?id=3301

都说这个题是三分题目 但它不是单峰吧 好怀疑 

我根据网上的代码写的  连第二组数据都过不了 但交上去 0ms 过啦

建议不要做这道题 如果有高手指点 那就跟好了

#include<iostream>

#include<cstdio>

#include<queue>

#include<cstring>

#include<set>

#include<cmath>

#include<algorithm>



using namespace std;



const int N=1005;

const double M=1000000.0;

const double PI=acos(-1.0);

const double eps=1e-10;

int x[N];

int y[N];

double sidemax(double k,int n)

{

    double x1,x2,y1,y2;

    x1=y1=M;

    x2=y2=-M;

    double xtemp,ytemp;

    for(int i=0;i<n;++i)

    {

        xtemp=x[i]*cos(k)-y[i]*sin(k);

        ytemp=y[i]*cos(k)+x[i]*sin(k);

        //cout<<xtemp<<" "<<ytemp<<endl;

        x1=min(x1,xtemp);

        x2=max(x2,xtemp);

        y1=min(y1,ytemp);

        y2=max(y2,ytemp);

    }

    //cout<<x1<<" "<<x2<<endl;

    return max(y2-y1,x2-x1);

}

int main()

{

    //freopen("data.txt","r",stdin);

    int T;

    scanf("%d",&T);

    while(T--)

    {

        int n;

        scanf("%d",&n);

        for(int i=0;i<n;++i)

        scanf("%d %d",&x[i],&y[i]);

        double l=0.0;

        double r=PI/2.0;

        //int I=0;

        while((r-l)>eps)

        {

            //cout<<++I<<endl;

            //cout<<l<<" TTTT "<<r<<endl;

            double mid=(r+l)/2.0;

            double midr=(mid+r)/2.0;

            if(sidemax(mid,n)<sidemax(midr,n))

            {

                r=midr;

            }else

            {

                l=mid;

            }

        }

        printf("%.2f\n",sidemax(l,n)*sidemax(l,n));



    }

    return 0;

}