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 <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef complex<double> Point;

#define PI acos(-1.0)
#define EPS 1e-10
const ll INF = 1e16;
const ll MOD = 1e9 + 7;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define rep(i,N) for(int i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define EQ(a,b) (abs((a)-(b))<EPS)
#define EQV(a,b) ( EQ((a).real(), (b).real()) && EQ((a).imag(), (b).imag()) )
#define fi first
#define se second
#define N_SIZE (1LL << 20)
#define NIL -1

ll mod_add(ll a, ll b) { return (a + b) % MOD; }
ll mod_sub(ll a, ll b) { return (a - b + MOD) % MOD; }
ll mod_mul(ll a, ll b) { return a*b % MOD; }

ll h,w;
int table[51][51];

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

void solve(int y,int x){
    table[y][x] = 0;
    rep(i,8){
        int ny = y + dy[i];
        int nx = x + dx[i];
        if(ny < 0 || ny >= h || nx < 0 || nx >= w)continue;
        if(table[ny][nx] == 1)solve(ny,nx);
    }
}

int main(){
    while(cin >> w >> h && w){
        rep(i,h){
            rep(j,w){
                cin >> table[i][j];
            }
        }
        ll ans = 0;
        rep(i,h){
            rep(j,w){
                if(table[i][j]){
                    ans++;
                    solve(i,j);
                }
            }
        }
        cout << ans << endl;
    }
}

C++: #include <iostream>
using namespace std;

#define PIAR pair<int, int>
int field[52][52];
int dx[] = {-1,  0, 1, 0, -1,  1, 1, -1};
int dy[] = {0 , -1, 0, 1, -1, -1, 1,  1};

void dfs(int x, int y){
	field[x][y] = 0;
	for(int i = 0; i < 8; i++){
		int nextX = x + dx[i];
		int nextY = y + dy[i];
		if(field[nextX][nextY] == 1) dfs(nextX, nextY);
	}
}

int main(){
    int w, h;
    while(cin >> w >> h, w != 0 && h != 0){
    	for(int i = 0; i < 52; i++){
    		for(int j = 0; j < 52; j++){
    			field[i][j] = 0;
    		}
    	}

        for(int i = 1; i <= h; i++){
            for(int j = 1; j <= w; j++){
                cin >> field[i][j];
            }
        }

        int island = 0;
        for(int i = 1; i <= h; i++){
            for(int j = 1; j <= w; j++){
                //島を探す
                if(field[i][j] == 1){
                	dfs(i, j);
                    island++;
                }

            }
        }

        cout << island << endl;
    }
}

C++: #include <iostream>
#include <vector>
using namespace std;
int ans;
int w, h;
//?§???????
const int mx[] = {-1, 0, 1, -1, 1, -1, 0, 1 };
const int my[] = { 1, 1, 1, 0, 0, -1, -1, -1};
vector<int> vx;
vector<int> vy;

vector<vector<int> > area;
int islands = 0;

//????±????????????¨????????¢?´¢
void dfs(int i,int j){
	for (int n = 0; n < vx.size(); n++){
		int x = j + vx[n];
		int y = i + vy[n];
		if (x >= 0 && x < w &&
			y >= 0 && y < h &&
			area[y][x] == 1){
			area[y][x] = 2;
			dfs(y,x);
		}
	}
}

int main(){
	for (int i = 0; i < 8; i++){
		vx.push_back(mx[i]);
		vy.push_back(my[i]);
	}
	while (1){
		cin >> w >> h;
		if (w == 0 && h == 0) break;
		//?????????
		islands = 0;
		area.clear();
		area = vector<vector<int> >(h, vector<int>(w));
		//??\???
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w; j++){
				cin >> area[i][j];
			}
		}
		//??¨??¢?´¢
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w; j++){
				if (area[i][j] == 1){
					islands++;
					area[i][j] = 2;
					dfs(i, j);
				}
			}
		}
		cout << islands << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<cstring>
#include<algorithm>
using namespace std;
#define INF (1<<29)

int c[52][52];
int w,h;
void del(int y,int x){
	c[y][x]=0;
	for(int i=-1;i<=1;i++){
		for(int j=-1;j<=1;j++){
			if(c[y+i][x+j])del(y+i,x+j);
		}
	}
}
int main(){
	while(cin>>w>>h,w||h){
		memset(c,0,sizeof(c));
		for(int i=1;i<=h;i++)
			for(int j=1;j<=w;j++)cin>>c[i][j];
		int ans=0;
		for(int i=1;i<=h;i++)
			for(int j=1;j<=w;j++)
				if(c[i][j]){
					ans++;
					del(i,j);
				}
		cout<<ans<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <queue>
#include <vector>
using namespace std;
typedef pair<int, int> P;

int w, h;
int data[50][50];	//data[row][col]

bool isRange(int r, int c) {
	return (r >= 0 && r < h && c >= 0 && c < w);
}

int main() {
	while (cin >> w >> h) {
		if (!w) break;
		for (int i = 0; i < h; i++)
			for (int j = 0; j < w; j++)
				cin >> data[i][j];
		
		int ans = 0;
		bool used[50][50] = {false};
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (!data[i][j] || used[i][j]) continue;
				ans++;
				
				//nurima-su (i, j) kara ikeru masu wo by bfs.
				queue<P> que;	//row, col
				que.push(P(i, j));
				while (!que.empty()) {
					int r = que.front().first;
					int c = que.front().second;
					que.pop();
					
					if (used[r][c]) continue;	//itidosika sirabenai (edakari)
					used[r][c] = true;	//visit
					
					for (int dr = -1; dr <= 1; dr++) {
						for (int dc = -1; dc <= 1; dc++) {
							if (dr == 0 && dc == 0) continue;
							if (!isRange(r + dr, c + dc) || !data[r + dr][c + dc]) continue;	//ikeruka hantei
							que.push(P(r + dr, c + dc));
						}
					}
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: //How Many Islands?
#include<bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0; i<n; i++)

int nx[8]={1,1,1,0,0,-1,-1,-1}, ny[8]={1,0,-1,1,-1,1,0,-1};
int w, h;
int mp[60][60];

void solve(int x, int y){
  if(x<0 || h<=x || y<0 || w<=y || mp[x][y]!=1)return;
  mp[x][y]=0;
  rep(i,8)solve(x+nx[i], y+ny[i]);
}

int main(){
  while(true){
    cin>>w>>h;
    if(w==0&&h==0)break;
    memset(mp, 0, sizeof(mp));
    rep(i,h)rep(j,w)cin>>mp[i][j];
    int cnt=0;
    rep(i,h)rep(j,w)if(mp[i][j]==1){solve(i, j); cnt++;}
    cout<<cnt<<endl;
  }
  return 0;
}