luogu 1337

这东西真玄学啊。。

在eps，delta，T之间改来改去。。。

在wa4，wa6，wa8之间轮转。

然后就过了。

爬山考虑合力然后移动即可。

eps要设的很小才行，布吉岛为森么

#include <bits/stdc++.h>
using namespace std;
typedef double db;
const db eps = 1e-14;
const db delta = 0.993;
const db INF = 1e100;
struct point{
    db x,y,w;
    point operator + (const point &k1) const{return (point){k1.x+x,k1.y+y};}
    point operator - (const point &k1) const{return (point){x-k1.x,y-k1.y};}
    point operator * (db k1) const{return (point){x*k1,y*k1};}
    db abs(){return sqrt(x*x+y*y);}
    db dis(point k1){return ((*this)-k1).abs();}
};
point p[1005];int n;
db mxx=1e18;point ans;
void sa(){
    db T = 2005;
    while (T>eps){
        db x=ans.x+(rand()*2-RAND_MAX)*T,y=ans.y+(rand()*2-RAND_MAX)*T;
        db z=0;
        for(int i=1;i<=n;i++)
            z+=sqrt((p[i].x-x)*(p[i].x-x)+(p[i].y-y)*(p[i].y-y))*p[i].w;
        if(z<mxx){
            mxx=z;
            ans={x,y};
        }
        T*=delta;
    }
}
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%lf%lf%lf",&p[i].x,&p[i].y,&p[i].w);
    sa();sa();sa();
    printf("%.3f %.3f\n",ans.x,ans.y);
}