求细胞数量

    1#include <bits/stdc++.h>
    2using namespace std;
    3using ll = long long;
    4using i128 = __int128;
    5const int inf = 1e9;
    6const ll INF = 1e18; //❄️
    7int main() {
    8    ios::sync_with_stdio(0); cin.tie(0); 
    9    int n, m; cin >> n >> m;
    10    vector<vector<char>> vis(n, vector<char>(m));
    11    for (int i = 0; i < n; i++) {
    12        string s; cin >> s;
    13        for (int j = 0; j < s.size(); j++) {
    14            if (s[j] == '0') vis[i][j] = 1;
    15        }
    16    }
    17    int cnt = 0;
    18    vector<pair<int, int>> dir = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
    19    auto bfs = [&](int i, int j) {
    20        queue<pair<int, int>> q;
    21        q.push({i, j});
    22        vis[i][j] = 1;
    23        while (!q.empty()) {
    24            auto[r, c] = q.front(); q.pop();
    25            for (int d = 0; d < dir.size(); d++) {
    26                int nr = r + dir[d].first, nc = c + dir[d].second;
    27                if (nr >= 0 && nr < n && nc >= 0 && nc < m && !vis[nr][nc]) {
    28                    vis[nr][nc] = 1;
    29                    q.push({nr, nc});
    30                }
    31            }
    32        }
    33        return;
    34    };
    35    for (int i = 0; i < n; i++) {
    36        for (int j = 0; j < m; j++) {
    37            if (!vis[i][j]) {
    38                bfs(i, j);
    39                cnt++;
    40            }
    41        }
    42    }
    43    cout << cnt << '\n';
    44    return 0;
    45}