状态压缩dp1

#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 20,M = 1 << 20;

int n;
int w[N][N];

//1、哪些点被用过
//2、目前停在哪个点上
int f[M][N];

int main()
{
    cin >> n;
    for(int i = 0;i < n;i ++) {
        for(int j = 0;j < n;j ++) {
            cin >> w[i][j];
        }
    }
    
    memset(f,0x3f,sizeof f);
    f[1][0] = 0;
    for(int i = 0;i < 1 << n;i ++) {
        for(int j = 0;j < n;j ++) {
            if(i >> j & 1) {
                for(int k = 0;k < n;k ++) {
                    if((i - (1 << j)) >> k & 1) {
                        f[i][j] = min(f[i][j],f[i - (1 << j)][k] + w[k][j]);
                    }
                }
            }
        }
    }
    
    cout << f[(1 << n) - 1][n - 1] << endl;
}