hrbustoj 2130 一笔画

基础状态压缩 转移方程为

 dp[j][i] = min(dp[j][i],dp[k][i^(1<<j)] + dis[k][j]);

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
double dp[16][1<<16];
double x[16],y[16];
double dis[16][16];
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        scanf("%d",&n);
        for(int i = 0;i < n;i++)
            scanf("%lf%lf",&x[i],&y[i]);
        for(int i = 0;i < n;i++)
            for(int j = 0;j < n;j++)
            dis[i][j] = sqrt((x[i]-x[j])*(x[i]-x[j]) + (y[i]-y[j])*(y[i]-y[j]));
        for(int i = 0;i < n;i++)
        {
            dp[i][0] = 0;
            for(int j = 1;j < (1<<n);j++)
                dp[i][j] = 99999999;
        }
        for(int i = 0;i < n;i++)
            dp[i][1<<i] = 0;
        for(int i = 0;i < (1<<n);i++)
        {
            for(int j = 0;j < n;j++)
            {
                for(int k = 0;k < n;k++)
                {
                    if( (1<<j)&i && (1<<k)&i && j != k)
                    dp[j][i] = min(dp[j][i],dp[k][i^(1<<j)] + dis[k][j]);
                }
            }
        }
        double Min = 99999999.0;
        for(int i = 0;i < n;i++)
        {
            if(dp[i][(1<<n) -1] < Min)
                Min = dp[i][(1<<n)-1];
        }
        printf("%.2lf\n",Min);
    }
    return 0;
}