Go: package main

import (
	"fmt"
)

func main() {
	var h, w int
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			return
		}
		matrix := make([][]int, h)
		Sean := make([][]bool, h)
		for i := 0; i < h; i++ {
			matrix[i] = make([]int, w)
			Sean[i] = make([]bool, w)
			for j := 0; j < w; j++ {
				fmt.Scan(&matrix[i][j])
			}
		}
		var count int
		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				if matrix[i][j] == 1 && Sean[i][j] == false {
					search(i, j, h, w, matrix, Sean)
					count++
				}
			}
		}
		fmt.Println(count)
	}
}
func search(x int, y int, h int, w int, matrix [][]int, Sean [][]bool) {
	if x < 0 || y < 0 || x >= h || y >= w || matrix[x][y] == 0 {
		return
	}
	if Sean[x][y] == true {
		return
	}

	Sean[x][y] = true

	search(x+1, y, h, w, matrix, Sean)
	search(x-1, y, h, w, matrix, Sean)
	search(x, y+1, h, w, matrix, Sean)
	search(x, y-1, h, w, matrix, Sean)
	search(x+1, y-1, h, w, matrix, Sean)
	search(x-1, y+1, h, w, matrix, Sean)
	search(x+1, y+1, h, w, matrix, Sean)
	search(x-1, y-1, h, w, matrix, Sean)
}

C++: #include <bits/stdc++.h>
 
#define loop(n, i) for(int i=0;i<n;i++)
#define all(v) v.begin(),v.end()

using namespace std;
using ll = long long;

int C[100][100] = {};
int vis[100][100] = {};

int dfs(int i, int j)
{
    int d[] = {1, 0, -1};
    if (!vis[i][j] && C[i][j]) {
        vis[i][j] = 1;
        loop (3, x) loop (3, y) dfs(i + d[x], j + d[y]);
    }
}

int main()
{
    while (1) {
        fill(C[0], C[99]+100, 0);
        fill(vis[0], vis[99]+100, 0);

        int w, h; cin >> w >> h;
        if (!w && !h) break;
        loop (h, i) loop (w, j) cin >> C[i+1][j+1];

        int ans = 0;
        loop (h, i) loop (w, j) {
            if (vis[i+1][j+1] || !C[i+1][j+1]) continue;
            ans++;
            dfs(i+1, j+1);
        }
        cout << ans << endl;
    }
    return 0;
}

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

int islands=0;
int w,h;
int field[50][50];
void bfs(int, int);

int main(){

  while(cin>>w>>h&&w!=0&&h!=0){

    for(int i=0;i<51;i++){
      for(int j=0;j<51;j++){
        field[i][j] = 0;
      }
    }

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        cin >> field[i][j];
//        cout << field[i][j] << " ";
      }
  //    cout << endl;
    }
   // cout << endl;
    int ans=0; 

    for(int i=0;i<w;i++){
      for(int j=0;j<h;j++){
        if(field[i][j]==1){
          field[i][j]=0;
          bfs(i,j);
          ans++;
        }
      }
    }
    /*   if(w==5&&h==4){
         for(int i=0;i<w;i++){
         for(int j=0;j<h;j++){
         cout << field[i][j] << " ";
         }
         cout << endl;
         }
         }*/
    cout << ans << endl;
  }

  return 0;
}

void bfs(int x, int y){
  if(x-1>=0&&field[x-1][y]==1){
    field[x-1][y]=0;
    bfs(x-1,y);
  }
  if(x+1<w&&field[x+1][y]==1){
    field[x+1][y]=0;
    bfs(x+1,y);
  }
  if(y-1>=0&&field[x][y-1]==1){
    field[x][y-1]=0;
    bfs(x,y-1);
  }
  if(y+1<h&&field[x][y+1]==1){
    field[x][y+1]=0;
    bfs(x, y+1);
  }
  if(x-1>=0&&y-1>=0&&field[x-1][y-1]==1){
    field[x-1][y-1]=0;
    bfs(x-1,y-1);
  }
  if(x+1<w&&y-1>=0&&field[x+1][y-1]==1){
    field[x+1][y-1]=0;
    bfs(x+1,y-1);
  }
  if(x-1>=0&&y+1<h&&field[x-1][y+1]==1){
    field[x-1][y+1]=0;
    bfs(x-1,y+1);
  }
  if(x+1<w&&y+1<h&&field[x+1][y+1]==1){
    field[x+1][y+1]=0;
    bfs(x+1,y+1);
  }
  return;
}