POJ 2386
BFS 求连通块
这题是八连通，注意别写错。
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
#define endl '
'
const int N = 200;
char g[N][N];
int n,m,ans;
int dx[8] = {0,0,1,-1,1,1,-1,-1};
int dy[8] = {1,-1,0,0,-1,1,-1,1};
struct node {
int x,y;
};
void bfs(int x,int y) {
queue<node> q;
q.push({x,y});
g[x][y] = '.';
while(q.size()) {
node t = q.front();
q.pop();
for(int i = 0;i < 8; ++i) {
int nx = t.x + dx[i],ny = t.y + dy[i];
if(nx >= 0 && nx < n && ny >= 0 && ny < m && g[nx][ny] == 'W' ) {
q.push({nx,ny});
g[nx][ny] = '.';
}
}
}
}
int main() {
ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
cin >> n >> m;
for(int i = 0;i < n; ++i)
for(int j = 0;j < m; ++j)
cin >> g[i][j];
for(int i = 0;i < n; ++i){
for(int j = 0;j < m; ++j) {
if(g[i][j] == 'W'){
bfs(i,j);
ans ++;
}
}
}
cout << ans << endl;
return 0;
}