1.多维初始化长度vector

    vector<vector<vector<bool>>> st(n + 1, vector<vector<bool>>(m + 1, vector<bool>(5)));
    //st维度为st[n + 1][m + 1][5];

2.函数传参数使用auto (c++20 可用)

int dfs(auto &st, int x, int y, int res)
//st为第1条初始化的三维vector

3.优先队列的重载

struct cmp{
    bool operator () (int &a,int &b){
        return dep[a]<dep[b];
    } 
};
priority_queue<int,vector<int>,cmp> q;