HDU - 1241 dfs or bfs [kuangbin带你飞]专题一

8个方向求联通块，经典问题。

AC代码

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
const int maxn = 100 + 5;

const int dx[] = {0,0,-1,1,-1,-1,1,1};
const int dy[] = {1,-1,0,0,1,-1,1,-1};

int n, m;
char G[maxn][maxn];
int vis[maxn][maxn];

void dfs(int x, int y){
	vis[x][y] = 1;
	for(int i = 0; i < 8; ++i){
		int px = x + dx[i], py = y + dy[i];
		if(px < 0 || py < 0 || px >= n || py >= m) continue;
		if(!vis[px][py] && G[px][py] != '*') dfs(px, py);
	}
}

int main(){
	while(scanf("%d%d", &n, &m) == 2 && n){
		memset(vis, 0, sizeof(vis));
		for(int i = 0; i < n; ++i) scanf("%s", G[i]);

		int ans = 0;
		for(int i = 0; i < n; ++i)
		for(int j = 0; j < m; ++j){
			if(G[i][j] == '@' && !vis[i][j]){
				++ans;
				dfs(i, j);
			}
		}
		printf("%d\n", ans);
	}

	return 0;
}

如有不当之处欢迎指出！