代码

#include <iostream>
#include <cstring>

using namespace std;
const int N = 21, M = 1 << N;
int w[N][N], f[M][N];
int main()
{
    int n;
    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 >> k & 1) && j != k)
                        f[i][j] = min(f[i][j], f[i - (1 << j)][k] + w[k][j]);
    cout<<f[(1 << n) - 1][n - 1];
    return 0;
}

核心

状压dp