Lake Counting

lake.cc

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
const int INF = 1001001001;

void dfs(vector<vector<string>> &vect, int x, int y, int N, int M) {
    vect[x][y] = ".";

    for (int dx = -1; dx <= 1; dx++) {
        for (int dy = -1; dy <= 1; dy++) {
            int nx = x + dx;
            int ny = y + dy;

            if (0 <= nx && nx < N && 0 <= ny && ny < M) {
                if (vect[nx][ny] == "W") {
                    dfs(vect, nx, ny, N, M);
                }
            }
        }
    }
}

int main() {
    int N;
    int M;
    cin >> N >> M;

    vector<vector<string>> data(N, vector<string>(M));

    // rep(i, vect.size()) cout << vect[i] << endl;

    rep(i, N) {
        string inputS;
        cin >> inputS;

        rep(j, M) { data.at(i).at(j) = inputS.at(j); }
    }

    int res = 0;
    rep(i, N) {
        rep(j, M) {
            if (data.at(i).at(j) == "W") {
                dfs(data, i, j, N, M);
                res++;
            }
        }
    }

    rep(i, N) {
        rep(j, M) { cout << data[i][j]; }
    }
    cout << res << endl;

    return 0;
}