Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

		route = make([][]int, h+2)
		route[0] = make([]int, w+2)
		for i := 1; i <= h; i++ {
			route[i] = make([]int, w+2)
			for j := 1; j <= w; j++ {
				route[i][j] = scanInt()
			}
		}
		route[h+1] = make([]int, w+2)

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

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

#define ll long long

using namespace std;

int w,h;

int f[100][100]={};
int cf[100][100] = {};



int main(){

    while(1){
        scanf("%d %d",&w,&h);
        if(w == 0 && h==0)break;

        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                scanf("%d",&f[i][j]);
            }
        }
        int ans = 0;
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                
                if(f[i][j] == 1 && cf[i][j]==0){
                    ans++;
                }
                for(int k=-1;k<2;k++){
                    if(i+k<0 || h <= i+k)continue;
                    for(int t=-1;t<2;t++){
                        if(j+t<0 || w <= j+t)continue;
                        if(f[i][j]==1&&f[i+k][j+t]==1 && cf[i+k][j+t]==0){
                            cf[i+k][j+t]=1;
                        }
                    }
                }
            }
        }
        cout << ans << endl;
    }

}

C++: #include <iostream>
#include <math.h>
#include <algorithm>
#include <vector>
using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;
				
				
vector<vector<int>> del_island(int i,int j,vector<vector<int>> v){	
	v[i][j] = 0;
	vector<vector<int>> answer = v;
	if(v[i-1][j] == 1){
		answer = del_island(i-1,j,answer);
	}
	if(v[i+1][j] == 1){
		answer = del_island(i+1,j,answer);
	}
	if(v[i][j-1] == 1){
		answer = del_island(i,j-1,answer);
	}
	if(v[i][j+1] == 1){
		answer = del_island(i,j+1,answer);
	}
	if(v[i-1][j-1] == 1){
		answer = del_island(i-1,j-1,answer);
	}
	if(v[i-1][j+1] == 1){
		answer = del_island(i-1,j+1,answer);
	}
	if(v[i+1][j-1] == 1){
		answer = del_island(i+1,j-1,answer);
	}
	if(v[i+1][j+1] == 1){
		answer = del_island(i+1,j+1,answer);
	}
	return answer;
}


int count_island(int w, int h,vector<vector<int>> v){
	int count = 0;
	for(int i = 1 ; i <= h ;i++){
		for(int j = 1 ;j <= w ;j++){
			//cout << v[i][j] ;
			if(v[i][j] == 1){
				count++;
				//cout << "hello" <<endl;
				v = del_island(i,j,v);
			}
		}
	}
	return count;
}
	
int main(){ 
	int w,h;
	vector<vector<int>> v(60,vector<int>(60,0));
	int count;

	while(1){
		cin >> w >> h;
		if(w == 0 && h == 0){
			break;
		}
		count = 0; 
		for(int i = 0; i < 60;i++){
			for( int j = 0; j < 60;j++){
				v[i][j] = 0;
			}
		}

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

		count = count_island(w,h,v);


		cout << count << endl;
	}
}

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;
}