Go: ///
// File:  1160.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:45:57 2018
//
package main

import (
	"fmt"
)

var w, h int
var graph [][]string

func dfs(visited [][]bool, x, y int) {
	visited[x][y] = true

	for i := -1; i <= 1; i++ {
		for j := -1; j <= 1; j++ {
			dx := x + i
			dy := y + j
			if 0 <= dx && dx < h && 0 <= dy && dy < w && graph[dx][dy] == "1" && !visited[dx][dy] {
				dfs(visited, dx, dy)
			}
		}
	}
}

func main() {
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			break
		}

		graph = make([][]string, h)
		for i := range graph {
			graph[i] = make([]string, w)
		}

		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				var s string
				fmt.Scan(&s)
				graph[i][j] = s
			}
		}

		visited := make([][]bool, h)
		for i := range visited {
			visited[i] = make([]bool, w)
		}

		count := 0
		for i := range graph {
			for j := range graph[i] {
				if graph[i][j] == "1" && !visited[i][j] {
					dfs(visited, i, j)
					count++
				}
			}
		}

		fmt.Println(count)
	}
}

C++: #include <cstdio>
#include <cstring>
using namespace std;

int w, h;
int map[100][100];
int island_number[100][100];

int angle[][2] = {
	{-1, 0}, {-1, -1}, {0, -1}, {1, -1},
	{1, 0}, {1, 1}, {0, 1}, {-1, 1}
};

void dfs(int y, int x)
{
	for (int i = 0; i < 8; i++){
		if (
		y + angle[i][0] >= 0 &&
		y + angle[i][0] <= w &&
		x + angle[i][1] >= 0 &&
		x + angle[i][1] <= h &&
		island_number[y + angle[i][0]][x + angle[i][1]] == (y + angle[i][0]) * h + x + angle[i][1]
		){
			island_number[y + angle[i][0]][x + angle[i][1]] = island_number[y][x];
			dfs(y + angle[i][0], x + angle[i][1]);
		}
	}
}

int main()
{
	
	while (scanf("%d %d", &w, &h), w + h){
		memset(island_number, 0, sizeof(island_number));
		
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w; j++){
				scanf("%d", &map[i][j]);
				if (map[i][j] == 1){
					island_number[i][j] = i * h + j;
				}
				else {
					island_number[i][j] = -1;
				}
			}
		}
		
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w; j++){
				if (island_number[i][j] == i * h + j){
					dfs(i, j);
				}
			}
		}
		
		bool ex[100 * 100] = {false};
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w; j++){
				if (island_number[i][j] >= 0){
					ex[island_number[i][j]] = true;
				}
//				printf("%d ", island_number[i][j]);
			}
//			puts("");
		}
		
		int cnt = 0;
		for (int i = 0; i < w * h; i++){
			cnt += ex[i];
		}
		
		printf("%d\n", cnt);
	}
	
	return 0;
}

C++: #include <iostream>

using namespace std;

int w,h;
int dx[8] = { -1 , -1 , -1 ,  0 , 0 ,  1 , 1 , 1};
int dy[8] = { -1 ,  0 ,  1 , -1 , 1 , -1 , 0 , 1};
int map[51][51];

void check(int x , int y){
	int mx,my;

	for(int i=0 ; i<8 ; i++){//üÍWûüð²×é
		mx = x + dx[i];
		my = y + dy[i];

		//tB[hOÉoÄ¢È¯êÎ²×é(0ÈãE³Èà)
		if(mx>=0 && mx<w && my>=0 && my<h){
			if(map[my][mx]==1){//¾Á½ç
				map[my][mx] = 2;//ñdÉ²×È¢½ßÉÊÌlðüêé
				check( mx , my );
			}
		}
	}
}

int main(){
	int count;//ÌðJEg·éÏ

	while(1){
		//ÏÌú»
		count = 0;
		
		//E³ÌüÍ
		cin >> w >> h;
		if(w==0 && h==0) break;//0 0ªüÍ³ê½çI¹

		//tB[hª©C©ÌîñðüÍ
		for(int y=0 ; y<h ; y++){
			for(int x=0 ; x<w ; x++){
				cin >> map[y][x];
			}
		}

		for(int y=0 ; y<h ; y++){
			for(int x=0 ; x<w ; x++){
				if(map[y][x]==1){//¾Á½çÄAÖðÄÑo·
					map[y][x] = 2;
					count++;
					check( x , y );
				}
			}
		}

		//¦ÌoÍ
		cout << count << endl;
	}

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int w, h;

vector<vector<int>> field(55, vector<int>(55));
vector<vector<int>> island(55, vector<int>(55, -1));

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

void dfs(int y, int x, int id) {
    island[y][x] = id;
    rep(i, 8) {
        int ny = y + dy[i]; int nx = x + dx[i];
        if (ny < 0 || ny >= h || nx < 0 || nx >= w || field[ny][nx] == 0) continue;
        if (island[ny][nx] != -1) continue;
        dfs(ny, nx, id);
    }
}

int main() {
    
    while (cin >> w >> h && w) {
        rep(i, h) {
            rep(j, w) { 
                cin >> field[i][j];
            }
        }

        rep(i, h) {
            rep(j, w) {
                island[i][j] = -1;
            }
        }

        int ans = 0;
        rep(y, h) {
            rep(x, w) {
                if (field[y][x] == 1 && island[y][x] == -1) {
                    dfs(y, x, ans);
                    ans++;
                } 
            }
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include<stdio.h>
#include<iostream>

int field[51][51];

void land(int x,int y){
	field[x][y]=0;

	for(int yy=-1;yy<=1;yy++){
		for(int xx=-1;xx<=1;xx++){
			if(field[x+xx][y+yy]==1) land(x+xx,y+yy);
		}
	}
	return;
}

int main(void){

	int w,h,kazu=0;

	scanf("%d %d",&w,&h);

	if(w==0||h==0) return 0;

	for(int i=0;i<h;i++){
		for(int j=0;j<w;j++){
			scanf("%d",&field[j][i]);
		}
	}

	for(int i=0;i<h;i++){
		for(int j=0;j<w;j++){

			if(field[j][i]==1){
				land(i,j);
				kazu++;
			}

		}
	}

	printf("%d",kazu);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int (i) = 0;(i) < (n) ; ++(i))
#define REPS(a,i,n) for(int (i) = (a) ; (i) < (n) ; ++(i))
#define REVERSE(i,n) for(int (i) = n-1;(i) >= 0 ; --i)
#define ALL(c) (c).begin() , (c).end()
#define LL long long
#define int LL
#define inf  (1LL << 60)
#define mod 1000000007
#define QUICK_CIN ios::sync_with_stdio(false); cin.tie(0);
#define lower lower_bound
#define upper upper_bound
#define ZERO(c,n) memset(&c[0],0,sizeof(int)*n)
#define ZERO2(c,n) memset(&c[0][0],0,sizeof(int)*n
#define pl(a) cout << ""#a": " << a << endl;
#ifdef _DEBUG
#define debug_io fstream cin("input.txt");ofstream cout("output.txt");
template<class T>fstream& operator>>(fstream& is, vector<T>& v)
{
	int n = v.size();
	REP(i, n) {
		is >> v[i];
	}
	return is;
}
#else
#define debug_io ;
#endif
#define debug_input debug_io
#define DOWN(T) std::greater<T>()
template<class T>istream& operator>>(istream& is, vector<T>& v)
{
	int n = v.size();
	REP(i, n) {
		is >> v[i];
	}
	return is;
}
using vs = vector<string>; using vi = vector<int>; using pii = pair<int, int>;
using psi = pair<string, int>; using vvi = vector<vi>; using pss = pair<string, string>;
using vpii = vector<pii>;
template<class T>bool valid(T x, T w) { return 0 <= x&&x < w; }
//int dx[4] = { 1, -1, 0, 0 }; int dy[4] = { 0, 0, 1, -1 };
//-----------------------------------------------------------------------------------------------
//-----------------------------------------------------------------------------------------------
//-----------------------------------------------------------------------------------------------

bool ed[55][55];
int dx[8] = { 0,0,1,-1,1,-1,1,-1 };
int dy[8] = { 1,-1,0,0,1,1,-1,-1 };

signed main()
{
	QUICK_CIN;
	debug_input;
	int w, h;
	while (cin >> w >> h, w + h) {
		vector<vi> tile(h,vi(w));
		REP(i, h) {
			REP(j, w) {
				cin >> tile[i][j];
			}
		}

		int ans = 0;
		REP(i, 55) {
			REP(j, 55) {
				ed[i][j] = false;
			}
		}

		REP(i, h) {
			REP(j, w) {
				if (tile[i][j] != 1)
					continue;
				queue<pii> q;
				q.push({ i,j });
				while (q.size()) {
					auto t = q.front();
					q.pop();
					auto y = t.first;
					auto x = t.second;
					if (ed[y][x]) {
						continue;
					}
					tile[y][x] = 2;
					ed[y][x] = true;
					REP(k, 8) {
						auto nx = min(w-1,max(0LL,x + dx[k]));
						auto ny = min(h-1,max(0LL,y + dy[k]));
						if (!ed[ny][nx]&&tile[ny][nx]==1) {
							q.push({ ny,nx });
						}
					}
				}
				ans++;
			}
		}
		cout << ans << endl;
	}
}