uva 10012

#include <iostream>#include <cstring>#include <vector>#include <algorithm>#include <fstream>#include <stdlib.h>#include <math.h>using namespace std;int ball_num,rank[10];double circu[10],ans,temp;double data[10][3];bool flag[10];// 1 is x, 2 is y and circu;double calcula(double r1,double r2){    return sqrt(pow(r1+r2,2)-pow(r1-r2,2));}void dps(int n){    double x=0,y=0,temp1,temp2;    // if okay    if(n==ball_num){        double left_most=99999999,right_most=-99999999;        for(int i=0;i<ball_num;i++){            temp1 = data[i][1]-data[i][2];            temp2 = data[i][1]+data[i][2];            if(temp1<left_most){left_most = temp1;}            if(temp2>right_most){right_most = temp2;}        }        if(right_most-left_most<ans){ans = right_most-left_most;}        //cout<<"find one "<<endl;        /*        for(int i =0;i<ball_num;i++){            cout<<data[i][1]<<" "<<data[i][2]<<endl;        }        */        return;    }    for(int i = 1;i<=ball_num;i++){        if(flag[i]==0){        if(n ==0){            x = y = circu[i];        }        else{            double max_x=0,temp_num;            for(int j = 0;j<n;j++){                temp_num = data[j][1];                //data[j][2] + circu[i]                temp_num+=calcula(data[j][2],circu[i]);                if(temp_num>max_x){max_x = temp_num;}            }            x = max_x;        }        y = circu[i];        data[n][1] = x; data[n][2] = y;        flag[i] = 1;        dps(n+1);        flag [i] = 0;    }    }}int main() {    //ifstream cin("ha.txt");    int t;    cin>>t;    while(t--){        cin>>ball_num;        for(int i=1;i<=ball_num;i++){            cin>>circu[i];        }        ans = 999999999;        memset(flag,0,sizeof(flag));        dps(0);        printf("%.3lf\n",ans);    }}