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<iostream>
#include<fstream>

using namespace std;

	ifstream fin;
	ofstream fout;

	//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp

	int gomi = 0;

	int a[52][52] = {};
	int check(int, int);

	int main(){

		fin.open("input.txt");
		fout.open("output.txt");

		//		int w = 0, h = 0;
		int width = 0, height = 0;
		int count = 0;


		while (1){
			for (int i = 0; i < 50; i++)
				for (int j = 0; j < 50; j++)
					a[i + 1][j + 1] = 0;

			cin >> width >> height;
			if (width == 0 && height == 0)break;

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					//初期化
					gomi = a[i + 1][j + 1] = 0;

					cin >> a[i + 1][j + 1];
				}
			}

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
				}
			}
			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					if (a[i + 1][j + 1] == 1){
						check(i + 1, j + 1);
						a[i + 1][j + 1] = 1;
						count++;
					//	cout << i + 1 << "  " << j + 1 << endl;
					}
				}
			}
//			cout << count << endl;
			fout << count << endl;

			//初期化
			count = 0;
			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					a[i + 1][j + 1] = 0;
				}
			}
		}
	}

	int check(int y, int x){
		if (a[y + 1][x] == 1){
			a[y + 1][x] = 0;
			check(y + 1, x);
		}
		//-----------------------------
		if (a[y][x + 1] == 1){
			a[y][x + 1] = 0;
			check(y, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x] == 1){
			a[y - 1][x] = 0;
			check(y - 1, x);
		}
		//-----------------------------
		if (a[y][x - 1] == 1){
			a[y][x - 1] = 0;
			check(y, x - 1);
		}
		//-----------------------------
		if (a[y + 1][x + 1] == 1){
			a[y + 1][x + 1] = 0;
			check(y + 1, x + 1);
		}
		//-----------------------------
		if (a[y + 1][x - 1] == 1){
			a[y + 1][x - 1] = 0;
			check(y + 1, x - 1);
		}
		//-----------------------------
		if (a[y - 1][x + 1] == 1){
			a[y - 1][x + 1] = 0;
			check(y - 1, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x - 1] == 1){
			a[y - 1][x - 1] = 0;
			check(y - 1, x - 1);
		}
		//-----------------------------
		return 0;
	}

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

int state[100][100];
bool reached[100][100];
int w,h;

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

void dfs(int x, int y) {

	if(x==0 || w<x || y==0 || h<y || state[x][y] == 0)
		return;
	if(reached[x][y] == true)
		return;

	reached[x][y]=true;

	for(int i=0; i<8; i++) {
		dfs(x+dx[i],y+dy[i]);
	}
}

int main() {

	while(1){
		cin >> w >> h;
		if(w==0 && h==0) {
			return 0;
		}
		memset(state, 0, sizeof(state));
		memset(reached, false, sizeof(reached));
		for(int i=1; i<=h; i++) {
			for(int j=1; j<=w; j++) {
				cin >> state[i][j];
			}
		}
		int count=0;
		for(int i=1; i<=w; i++) {
			for(int j=1; j<=h; j++) {
				if(reached[i][j]==true || state[i][j] == 0)
					continue;
				else{
					dfs(i,j);
					count++;
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
typedef long long ll;
#define rep(i,s,n) for(int i = s;i<n;i++)
#define repe(i,s,n) for(int i = s;i<=n;i++)
static const ll maxLL = (ll)1 << 62;

//dfs(bool型)
int dy[]={-1,0,1,0,1,-1,-1,1};
int dx[]={0,1,0,-1,1,1,-1,-1};
bool visited[1000][1000];
int t[1000][1000];
char copy_t[1000][1000];
int h,w;
int si,sj;

void dfs(int y,int x){
  if(y<=0||x<=0)return;
  if(y>h||x>w)return;
  if(t[y][x]==0)return;
  if(visited[y][x])return;
  visited[y][x]=true;
  for(int i=0;i<8;i++){
    int ny=y+dy[i];
    int nx=x+dx[i];
    dfs(ny,nx);
  }
  return;
}

int main(){
    while(0){
    int cnt=0;
    cin>>w>>h;
    if(w==\0 && h==\0)break;
    repe(i,1,h){
        for(int j=1;j<=w;j++){
            cin>>t[i][j];
        }
    }
    repe(i,1,h){
        repe(j,1,w){
             if(t[i][j]==1 && visited[i][j]==false)cnt++;
        dfs(i,j);
        }
    }
    cout<<cnt<<endl;
}
return 0;
}

C++: #include <iostream>
#include <map>
#include <algorithm>
#include <vector>
#include <string>
#include <utility>
#include <queue>
#define INF 1e9+7
#define rep(i,n) for(int i=0;i<n;i++)
#define NO cout<<"NO"<<endl;
#define YES cout << "YES"<<endl;
#define No cout << "No"<<endl;
#define Yes cout << "Yes"<<endl;
#define all(a) a.begin(),a.end()
#define P pair<int,int>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

//(int)'a'は97 (int)'A'は65 (int)'1'は49
//おまじない

int main(){
    
    while(true){
        int h,w;
        int m[50][50];
        bool used[50][50]={0};
        int dx[]={-1,0,1};
        int dy[]={-1,0,1};
        int ans=0;
        
        cin >> w>>h;
        if(h==0&&w==0)break;
        
        rep(i,h){
            rep(j,w){
                cin >> m[i][j];
            }
        }
        
        rep(i,h){
            rep(j,w){
                if(m[i][j]==1&&!used[i][j]){
                    ans++;
                    queue<P> que;
                    que.push(P(i,j));
                    while(!que.empty()){
                        P p=que.front();que.pop();
                        int x = p.second,y=p.first;
                        rep(a,3){
                            rep(b,3){
                                int nx=x+dx[a],ny=y+dy[b];
                                if(nx>=0&&nx<w&&ny>=0&&ny<h&&m[ny][nx]==1&&!used[ny][nx]){
                                    que.push(P(ny,nx));
                                    used[ny][nx]=true;
                                }
                            }
                        }
                    }
                }
            }
        }
        cout << ans<<endl;
    }
    
    return 0;
}