python/TangDou/XiTi/1381_dfs.cpp

#include <bits/stdc++.h>

using namespace std;
const int N = 110;
int g[N][N];
int n, m;

int dx[] = {-1, 0, 1, 0}; //上右下左
int dy[] = {0, 1, 0, -1}; //上右下左

//总个数
int ans;

//深度优先搜索
void dfs(int x, int y) {
    g[x][y] = 0; //标识为0
    for (int i = 0; i < 4; i++) {
        int tx = x + dx[i], ty = y + dy[i];
        if (tx < 1 || tx > n || ty < 1 || ty > m) continue;
        if (g[tx][ty]) dfs(tx, ty);
    }
}

int main() {
    cin >> n >> m;
    //黑色在方格图中被标为1，白色格子标为0
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            cin >> g[i][j];

    //深度优先搜索
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            //发现有黑色的方块
            if (g[i][j]) {
                //黑色方块数+1
                ans++;
                //深搜
                dfs(i, j);
            }

    cout << ans << endl;
    return 0;
}