BFS，4WA+1MLE+5AC = 50分

这是我的BFS代码

#include <iostream>
#include <queue>

using namespace std;

#define int long long
#define TRACE 1
#define tcout TRACE && cout
#define el printf("\n")
#define inf 0x7fffffff

int n, m;
int a[110][110];
int ans[10000010];
int cnt;
int x1, y1, x2, y2;
int maxn = -inf, minn = inf;
int res = -inf;

struct Node{
    int x, y, s;
    Node(){

    }
    Node(int _x, int _y, int _s){
        x = _x;
        y = _y;
        s = _s;
    }
};

int fx[] = {-1, 0, 0, 1};
int fy[] = {0, -1, 1, 0};

queue<Node> q;

void bfs(int x, int y){
    q.push(Node(x, y, 0));

    while(!q.empty()){
        int x = q.front().x;
        int y = q.front().y;
        int s = q.front().s;

        q.pop();

        if(x == x2 && y == y2){
            ans[++cnt] = s+1;
        }

        for(int i=0; i<4; i++){
            int dx = x + fx[i];
            int dy = y + fy[i];
            if(dx >= 1 && dy >= 1 && dx <= n && dy <= m){
                if(a[dx][dy] < a[x][y]){
                    q.push(Node(dx, dy, s+1));
                }
            } 
        }
    }
}

signed main()
{
    cin >> n >> m;
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            cin >> a[i][j];
            if(a[i][j] > maxn){
                maxn = a[i][j];
                x1 = i, y1 = j;
            }
            if(a[i][j] < minn){
                minn = a[i][j];
                x2 = i, y2 = j;
            }
        }
    }
    bfs(x1, y1);
    for(int i=1; i<=cnt; i++){
        res = max(res, ans[i]);
    }
    cout << res;
    el;
    return 0;
}

这是我的提交记录

向大佬们求助！！