联通快--模板

求联通快模板
Uva 油田

#include<cstdio>
#include<iostream>
#include<string.h>
using namespace std;
const int maxn = 1000 + 5;
char g[maxn][maxn];
int m, n, id[maxn][maxn];

void dfs(int row, int col, int c) {
    if (row < 0 || row >= m || col < 0 || col >= n) {
        return;
    }
    if (id[row][col] > 0 || g[row][col] != '@') {
        return;
    }
    id[row][col] = c;
    for (int i = -1; i<2; i++) 
        for (int j = -1; j<2; j++) 
            if (i != 0 || j != 0) dfs(row + i, col + j, c);
}

int main() {
    scanf("%d %d", &m, &n);
    for (int i = 0; i < m; i++) {
        scanf("%s", g[i]);
    }
    memset(id, 0, sizeof(id));
    int cnt = 0;
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            if (id[i][j] == 0 && g[i][j] == '@')
                dfs(i, j, ++cnt);
        }
    }
    printf("%d
", cnt);
    return 0;
}