这学期开始刷《算法竞赛进阶指南》，暂定寒假前刷完这本书，正常进度的话，一周刷40页左右。

传送门

#include <bits/stdc++.h>

using namespace std;
int f[1 << 20][21], weight[21][21], n;

int main() {
    //freopen("in","r",stdin);
    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            cin >> weight[i][j];
    }
    memset(f, 0x3f, sizeof(f));
    f[1][0] = 0;
    for (int i = 1; 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] + weight[k][j]);
                }
            }
        }
    }
    cout << f[(1 << n) - 1][n - 1] << endl;
    return 0;
}