题解 | 数水坑

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int N = 105;
char g[N][N];
bool v[N][N];
int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0, 0, 1, -1, 1, -1};

int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        cin >> g[i];
    }
    int c = 0;
    queue<pair<int, int>> q;

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (g[i][j] == 'W' && !v[i][j]) {
                c++;
                v[i][j] = true;
                q.push({i, j});

                while (q.size()) {
                    auto [x, y] = q.front();
                    q.pop();
                    for (int i = 0; i < 8; i++) {
                        int nx = x + dx[i];
                        int ny = y + dy[i];
                        if (nx >= 0 && nx < n && ny >= 0 && ny < m &&
                                !v[nx][ny] && g[nx][ny] == 'W') {
                            v[nx][ny] = true;
                            q.push({nx, ny});
                        }
                    }
                }
            }
        }
    }
    cout << c;
}