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 <algorithm>
#include <vector>
using namespace std;

typedef pair<int,int> P;

const int dx[] = { 0, 1, 0,-1, 1, 1,-1,-1};
const int dy[] = { 1, 0,-1, 0, 1,-1, 1,-1};
int h, w;
vector<vector<int> > islands(50, vector<int>(50));

void bfs (int i, int j) {
    queue<P> q;
    q.push(P(i,j));
    while (q.size()) {
        const P p = q.front();
        q.pop();
        for (int i = 0; i < 8; i++) {
            int x = p.first + dx[i], y = p.second + dy[i];
            if (0 <= x && x < w && 0 <= y && y < h && islands[x][y]) {
                islands[x][y] = 0;
                q.push(P(x,y));
            }
        }
    }
}

int main ()
{
    while (cin >> h >> w, (h || w)) {
        for (int i = 0; i < w; i++) {
            for (int j = 0; j < h; j++) {
                cin >> islands[i][j];
            }
        }

        int count = 0;
        for (int i = 0; i < w; i++) {
            for (int j = 0; j < h; j++) {
                if (islands[i][j] == 1) {
                    count++;
                    islands[i][j] = 0;
                    bfs(i, j);
                }
            }
        }
        cout << count << endl;
    }


    return 0;
}

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

struct pos {
    int x, y;
};

int main() {

    while (true) {
        int W, H;
        cin >> W >> H;
        if (W*H == 0) break;

        bool C[W][H] = {};
        rep(y, H) rep(x, W) cin >> C[x][y];

        int cnt = 0;
        stack<pos> s;
        rep(y, H) rep(x, W) {
            if (C[x][y]) {
                cnt++;
                s.push({x, y});
            }
            while (!s.empty()) {
                pos p = s.top();
                s.pop();
                C[p.x][p.y] = false;
                for (int dx=-1; dx<=1; dx++) {
                    for (int dy=-1; dy<=1; dy++) {
                        int nx = p.x+dx, ny = p.y+dy;
                        if ((nx<0) || (nx>=W) || (ny<0) || (ny>=H)) continue;
                        if (C[nx][ny]) {
                            s.push({nx, ny});
                            // cout << p.x << p.y << " " << nx << ny << endl;
                        }
                    }
                }
            }
        }
        cout << cnt << endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>
 
#define rep(i,n) for(ll i=0;i<n;++i)
#define ALL(a) (a).begin(),(a).end()
 
using namespace std;
using ll  = long long;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;
 
const ll MOD  = 1e9+7;
const ll LINF = 1LL << 60;
const int INF = 1e9 + 7;

int mv[3] = {1, 0, -1};

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

void dfs(int y, int x){

    rep(i, 3)rep(j, 3){
        int dx = x + mv[i];
        int dy = y + mv[j];

        if(dx < 0 || dx >= w || dy < 0 || dy >= h)continue;

        if(atlas[dy][dx] == 1){
            atlas[dy][dx] = 0;
            dfs(dy, dx);
        }
    }
}

int main(){
    vector<int> ans;
    while(true){
        cin >> w >> h;

        if(h + w == 0)break;

        rep(i, h)rep(j, w){
            cin >> atlas[i][j];
        }

        int res = 0;
        rep(i, h)rep(j, w){
            if(atlas[i][j] == 1){
                atlas[i][j] = 0;
                res++;

                dfs(i, j);
            }
        }

        ans.push_back(res);
    }

    rep(i, ans.size()){
        cout << ans[i] << endl;
    }
}

C++: #include <bits/stdc++.h>

using namespace std;

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

int w, h;
int c[55][55];

void dfs(int i, int j) {
    if(c[i][j] == 0) return;
    
    c[i][j] = 0;
    dfs(i-1, j-1);
    dfs(i-1, j);
    dfs(i-1, j+1);
    dfs(i  , j-1);
    dfs(i  , j+1);
    dfs(i+1, j-1);
    dfs(i+1, j);
    dfs(i+1, j+1);
}

int main() {
	while(1) {
	    cin >> w >> h;
	    if(w == 0 && h == 0) break;
	    
	    rep(i, h) rep(j, w) cin >> c[i+1][j+1];
	    
	    int ans = 0;
	    rep(i, h) {
	        rep(j, w) {
	            if(c[i+1][j+1] == 0) continue;
	            dfs(i+1, j+1);
	            ans++;
	        }
	    }
	    cout << ans << endl;
	}
}

C++: #include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <cstring>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <stack>
#include <queue>

using namespace std;
typedef long long LL;
typedef pair<int, int> PII;
static const double EPS = 1e-5;

#define FOR(i,k,n) for (int i=(k); i<(int)(n); ++i)
#define REP(i,n) FOR(i,0,n)
const int dx[8] = {0,1,1,1,0,-1,-1,-1};
const int dy[8] = {1,1,0,-1,-1,-1,0,1};
int w,h,grid[51][51];
void s(int x, int y){
  grid[y][x] = 0;
  REP(r,8){
    if(x+dx[r]>=0&&x+dx[r]<w&&y+dy[r]>=0&&y+dy[r]<h&&grid[y+dy[r]][x+dx[r]]){
      s(x+dx[r],y+dy[r]);
    }
  }
} 


int main(void){
  while(cin>>w>>h){
    if(w==0) break;
    REP(y,h)
      REP(x,w)
        cin>>grid[y][x];
    int c = 0;
    REP(y,h)
      REP(x,w)
        if(grid[y][x]){
          c++;
          s(x,y);
        }
    cout<<c<<endl;
  }
  return 0;
}

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

#define INF 1.1e9
#define LINF 1.1e18
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define BIT(x,n) bitset<n>(x)
#define PI 3.14159265358979323846

typedef long long ll;
typedef pair<int,int> P;
typedef pair<ll,P> PP;

//-----------------------------------------------------------------------------

int h,w;
int fld[50][50];
int dx[]={1,-1,0,0,1,1,-1,-1},dy[]={0,0,1,-1,-1,1,-1,1};

void bfs(int sy,int sx) {
	queue<P> q;
	fld[sy][sx]=0;
	q.push(P(sx,sy));
	while(!q.empty()) {
		P p=q.front();q.pop();
		REP(i,8) {
			int nx=p.fi+dx[i],ny=p.se+dy[i];
			if(nx<0||nx>=w||ny<0||ny>=h||fld[ny][nx]==0) continue;
			fld[ny][nx]=0;
			q.push(P(nx,ny));
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	while(true) {
		cin>>w>>h;
		if(w==0) break;
		REP(i,h) REP(j,w) cin>>fld[i][j];
		int cnt=0;
		REP(i,h) {
			REP(j,w) {
				if(fld[i][j]==1) {
					cnt++;
					bfs(i,j);
				}
			}
		}
		cout<<cnt<<endl;
	}

	return 0;
}