island_bfs

#include <iostream>

using namespace std;

int N, M;
int island[52][52];
int color[52][52];
int dx[8] = {0, -1, 0, 1, -1, -1, 1, 1};
int dy[8] = {-1, 0, 1, 0, -1, 1, -1, 1};

int bfs(int x, int y, int c){
	int queue[2510][2] = {0,};
	int head=0, tail=0;
	queue[head][0]=x;
	queue[head++][1]=y;
	color[x][y] = c;
	while(head>tail){
		int qx = queue[tail][0], qy = queue[tail++][1];
		for(int i=0; i<8; i++){
			int to_x = qx + dx[i];
			int to_y = qy + dy[i];
			if(to_x ==0 || to_x == N+1 || to_y == 0 || to_y == M + 1) continue;
			if(!island[to_x][to_y] || color[to_x][to_y]) continue;
			color[to_x][to_y] = c;
			queue[head][0] = to_x;
			queue[head++][1] = to_y;
		}
	}
	return 0;
}

int main(int argc, char* argv[]) {
	while(true){
		int col = 1;
		scanf("%d %d", &M, &N);
		if(N==0 && M==0) break;
		for(int i=1; i<=N; i++){
			for(int j=1; j<=M; j++){
				scanf("%d", &island[i][j]);
				color[i][j] = 0;
			}
		}
		for(int i=1; i<=N; i++){
			for(int j=1; j<=M; j++){
				if(!color[i][j] && island[i][j]) bfs(i, j, col++);
			}
		}
		printf("%d\n", col-1);
	}
	return 0;
}