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<queue>
#include<cstring>
using namespace std;
int x[90][90], col[90][90], h, w, c, i, j, k, l, p, q;
queue<int>Q, R;
int main() {
	while (true) {
		c = 0;
		memset(col, 0, sizeof(col));
		cin >> w >> h;
		if (h == 0) { break; }
		for (i = 0; i < h; i++) { for (j = 0; j < w; j++) { cin >> x[i][j]; } }
		for (i = 0; i < 50; i++) {
			for (j = 0; j < 50; j++) {
				if (x[i][j] == 1 && col[i][j] == 0) {
					c++;
					col[i][j] = c;
					Q.push(i * 100 + j);
					while (!Q.empty()) {
						while (!Q.empty()) {
							p = Q.front() / 100;
							q = Q.front() % 100;
							for (k = -1; k < 2; k++) {
								for (l = -1; l < 2; l++) {
									if (x[p + k][q + l] == 1 && col[p + k][q + l] == 0) {
										col[p + k][q + l] = c;
										R.push((p + k) * 100 + q + l);
									}
								}
							}
							Q.pop();
						}
						while (!R.empty()) {
							Q.push(R.front());
							R.pop();
						}
					}
				}
			}
		}
		cout << c << endl;
	}
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <cstring>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int W, H;
int c[50][50];
int vy[8] = {-1,-1,0,1,1,1,0,-1};
int vx[8] = {0,1,1,1,0,-1,-1,-1};
void calc(int y, int x) {
  if(y < 0 || y >= H || x < 0 || x >= W) return;
  if(c[y][x] == 0) return;
  visited[y][x] = 0;
  FOR(i,0,8) calc(y+vy[i],x+vx[i]);
  return;
}
int main()
{
  while(cin >> W >> H, (W || H)) {
    CLR(visited);
    FOR(y,0,H) FOR(x,0,W) cin >> c[y][x];
    int ans = 0;
    FOR(y,0,H) {
      FOR(x,0,W) {
        if(c[y][x] == 0) continue;
        calc(y, x);
        ans++;
      }
    }
    cout << ans << endl;
  }
  return 0;
}

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

//repetition
#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i, n) for(ll i = 0; i < (ll)(n); i++)

//container util
#define all(x) (x).begin(),(x).end()

//typedef
typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VLL;
typedef vector<VLL> VVLL;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;

//const value
//const ll MOD = 1e9 + 7;
const int dx[] = {0,0,1,1,1,-1,-1,-1};
const int dy[] = {1,-1,0,1,-1,0,1,-1};

//conversion
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
inline ll toLL(string s) {ll v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

void dfs(int ci, int cj, VVI& board, VVI& visited, int h,int w){
  visited[ci][cj] = 1;
  rep(dir,8){
    if((ci + dy[dir]) < h && (cj + dx[dir]) < w &&
       (ci + dy[dir]) >= 0 && (cj + dx[dir]) >= 0  &&
       visited[(ci + dy[dir])][(cj + dx[dir])] == 0 &&
       board[(ci + dy[dir])][(cj + dx[dir])] == 1){
      dfs((ci + dy[dir]),(cj + dx[dir]),board,visited,h,w);
    }
  }
}

void solve(int h, int w){
  VVI board(h,VI(w));
  rep(i,h)rep(j,w) cin >> board[i][j];
  VVI visited(h,VI(w,0));
  int cnt = 0;
  rep(i,h)rep(j,w){
    if(board[i][j] == 1 && visited[i][j] == 0){
      dfs(i,j,board,visited,h,w);
      cnt++;
      //cout << i << ' ' << j << endl;
    }
  }
  cout << cnt << endl;
}
int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  int h,w;
  while(true){
    cin >> w >> h;
    if(h == 0 &&  w == 0){
      break;
    }
    solve( h,  w);
  }
  return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T> V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T> mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }

/*
 <url:http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */

int w,h;
int solve(){
    int res = 0;
    vector<vector<int>> grid(h+2,vector<int>(w+2));
    for(int i = 1; i <= h; i++) for(int j = 1; j <= w;j++) cin >> grid[i][j];
    for(int i = 1; i <= h; i++) for(int j = 1; j <= w;j++){
        if(grid[i][j]){
            queue<pii> q; q.push({i,j});
            while(q.size()){
                int y,x;  tie(y,x) = q.front(); q.pop();
                if(grid[y][x] == 0) continue;
                grid[y][x] = 0;
                for(int dy = -1; dy <= 1; dy++){
                    for(int dx = -1; dx <= 1; dx++){
                        q.push({y+dy,x+dx});
                    }
                }
            }
            res++;
        }
    }
    return res;
}
int main(void) {
    cin.tie(0); ios_base::sync_with_stdio(false);
    while(cin >> w >> h,w){
        cout << solve() << endl;
    }
    return 0;
}