10分求助

#include <iostream>
using namespace std;

int used[105][105];
char a[105][105];
int wx[4] = {-1, 0, 0, 1};
int wy[4] = {0, -1, 1, 0};

void dfs(int x, int y) {
    if(used[x][y] == 1 || a[x][y] != 'w') return;
    used[x][y] = 1;
    for (int i = 0; i < 4; ++i) {
        dfs(x + wx[i], y + wy[i]);
    }
}

int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            cin >> a[i][j];
        }
    }
    int cnt = 0;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            if(used[i][j] == 0 && a[i][j] == 'w') {
                dfs(i, j);
                cnt++;
            }
        }
    }
    cout << cnt - 1 + 1;
    return 0;
}