UVa 572

dfs寻找连通块，floodfill

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxm= 105;
const int maxn= 105;

char ld[maxm][maxn];
int k[maxm][maxn];
int m, n;

void dfs(int x, int y, int c)
{
	if (x< 0 || y< 0 || x>= m || y>= n){
		return;
	}
	if (k[x][y]> 0 || '@'!= ld[x][y]){
		return;
	}
	k[x][y]= c;

	for (int dx= -1; dx< 2; ++dx){
		for (int dy= -1; dy< 2; ++dy){
			if (dx || dy){
				dfs(x+dx, y+dy, c);
			}
		}
	}
}

int main()
{
	while (1){
		scanf("%d %d", &m, &n);
		if (0== m){
			break;
		}
		memset(ld, 0, sizeof(ld));
		memset(k, -1, sizeof(k));
		for (int i= 0; i< m; ++i){
			for (int j= 0; j< n; ++j){
				scanf(" %c", &(ld[i][j]));
			}
		}
		int ans= 0;

		for (int i= 0; i< m; ++i){
			for (int j= 0; j< n; ++j){
				if ('@'== ld[i][j] && k[i][j]<= 0){
					dfs(i, j, ++ans);
				}
			}
		}

		printf("%d
", ans);
	}

	return 0;
}