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;}

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