大佬们帮帮忙

#include <bits/stdc++.h>
using namespace std;
int n, m;
const int max_n = 1100;
bool vis[max_n][max_n] = {false}; 
char mp[max_n][max_n];
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
struct node {
    int x;
    int y;
};
int bfs(int x, int y) {
    queue<node> q;
    q.push({x, y});
    vis[x][y] = true;
    int cnt = 0;
    while (!q.empty()) {
        node k = q.front();
        q.pop();
        cnt++;
        for (int i = 0; i < 4; i++) {
            int nx = k.x + dx[i];
            int ny = k.y + dy[i];
            if (nx >= 1 && nx <= n && ny >= 1 && ny <= m && mp[nx][ny] == '0' &&!vis[nx][ny]) {
                q.push({nx, ny});
                vis[nx][ny] = true;
            }
        }
    }
    return cnt;
}
int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> mp[i][j];
        }
    }

    int Cnt = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (mp[i][j] == '0' &&!vis[i][j]) {
                bool isd = true;
                for (int k = 0; k < 4; k++) {
                    int nx = i + dx[k];
                    int ny = j + dy[k];
                    if (nx >= 1 && nx <= n && ny >= 1 && ny <= m && mp[nx][ny]!= '*') {  // 修正判断被包围的逻辑
                        isd = false;
                        break;
                    }
                }
                if (isd) {
                    Cnt += bfs(i, j);
                }
            }
        }
    }
    cout <<Cnt << endl;
    return 0;
}