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>
using namespace std;
int w, h;
int c[55][55];

void dfs(int y, int x) {
    c[y][x] = 0;
    for (int dh = -1; dh <= 1; dh++) {
        for (int dw = -1; dw <= 1; dw++) {
            int nh = y + dh, nw = x + dw;
            if (0 <= nh && 0 <= nw && nh < h && nw < w && c[nh][nw]) {
                dfs(nh, nw);
            }
        }
    }
}

int main() {
    while (cin >> w >> h) {
        if (w == 0 && h == 0) break;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) cin >> c[i][j];
        }
        int ans = 0;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (c[i][j]) {
                    ans++;
                    dfs(i, j);
                }
            }
        }
        cout << ans << endl;
    }
}

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

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

int fill(vector<vector<bool> >& map, int y, int x){
    if(!map[y][x]) return 0;
    map[y][x] = false;
    for(int i=0; i<8; i++){
        fill(map, y+dy[i], x+dx[i]);
    }
    return 1;
}
        
int main(){
    while(1){
        int w,h;
        cin >> w >> h;
        if(w==0) break;

        vector<vector<bool> > map(h+2, vector<bool>(w+2, false));
        for(int i=1; i<=h; i++){
            for(int j=1; j<=w; j++){
                int tmp;
                cin >> tmp;
                if(tmp==1) map[i][j]=true;
            }
        }

        int count=0;
        for(int i=1; i<=h; i++){
            for(int j=1; j<=w; j++){
                count+= fill(map, i,j);
            }
        }
        cout << count << endl;
    }   
    return 0;
}

C++: //
//AOJ vol11-1160
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp
//20170616
//640009E
//Yang Bo
//

#include <iostream>

using namespace std;

int a[50][50];
int h, w;

int recursion(int y, int x)
{
  int number = 1;
  a[y][x] = 0;

  if (x < w - 1)
    if (a[y][x + 1] == 1)
      number = recursion(y, x + 1);
  if (y < h - 1)
    if (a[y + 1][x] == 1)
      number = recursion(y + 1, x);
  if (x > 0)
    if (a[y][x - 1] == 1)
      number = recursion(y, x - 1);
  if (y > 0)
    if (a[y - 1][x] == 1)
      number = recursion(y - 1, x);
  if (y < h - 1 && x < w - 1)
    if (a[y + 1][x + 1] == 1)
      number = recursion(y + 1, x + 1);
  if (y < h - 1 && x > 0)
    if (a[y + 1][x - 1] == 1)
      number = recursion(y + 1, x - 1);
  if (y > 0 && x < w - 1)
    if (a[y - 1][x + 1] == 1)
      number = recursion(y - 1, x + 1);
  if (y > 0 && x > 0)
    if (a[y - 1][x - 1] == 1)
      number = recursion(y - 1, x - 1);
  

  //cout << "recursion(" << y << ", "<< x << ") = " << number << endl;
  return number;
}

int main()
{
  while (cin >> w >> h) {
    if (w == 0)
      break;
    else {
      for (int i = 0; i < h; i++) {
	for (int j = 0; j < w; j++) {
	  cin >> a[i][j]; //??\???
	}
      }
      int ans = 0;
      for (int i = 0; i < h; i++) {
	for (int j = 0; j < w; j++) {
	  if (a[i][j] == 1) {
	    //cout << "i = " << i << " ,j = " << j << endl;
            ans += recursion(i, j);
	  }
	}
      }
      cout << ans << endl;
    }
  }
}

/*
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*/

C++: #include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <functional>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>
#include <cassert>
using namespace std;
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define EACH(t,i,c) for(t::iterator i=(c).begin(); i!=(c).end(); ++i)
const double EPS = 1e-10;
const double PI  = acos(-1.0);

int search(int y,int x,int w,int h,vvi &v){
	int dx[] = {-1,0,1,1,1,0,-1,-1};
	int dy[] = {-1,-1,-1,0,1,1,1,0};
	if(v[y][x] == 1){
		v[y][x] = 0;
		for(int i=0;i<8;i++){
			if(y+dy[i] >= 0 && y+dy[i] < h && x+dx[i] >= 0 && x+dx[i] < w){
				search(y+dy[i],x+dx[i],w,h,v);
			}
		}
		return 1;
	}
	return 0;
}

int main(){
	int w,h;
	while(1){
		cin >> w >> h;
		if(w == 0 && h == 0){
			break;
		}
		vector<vector<int> > v(h,vector<int>(w));
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin >> v[i][j];
			}
		}
		int cnt = 0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cnt += search(i,j,w,h,v);
			}
		}
		cout << cnt << endl;
	}
}

C++: #include <iostream>
#include <vector>
using namespace std;
#define MAX 50

int c[MAX][MAX];

void dfs(int w, int h, int x, int y);
int main(int argc, char const *argv[]){
    int w, h, ans;

    while (cin>>w>>h, w || h){
        ans = 0;
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                cin>>c[i][j];
            }
        }
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                if (c[i][j] == 1){
                    dfs(w, h, j, i);
                    ans++;
                }
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}

void dfs(int w, int h, int x, int y){
    int dx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
    int dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};
    c[x][y] = 0;

    for (int i = 0; i < 8; i++){
        int nx = x + dx[i];
        int ny = y + dy[i];

        if (0 <= nx && nx < w && 0 <= ny && ny < h && c[nx][ny] == 1){
            dfs(w, h, nx, ny);
        }
    }
    return;
}