Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout
	cnt := 0

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
		cnt = 0
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)
	for solve(scanner, writer) {

	}
	for i := 0; i < cnt; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
	writer.Flush()
}

func solve(scanner *bufio.Scanner, writer *bufio.Writer) bool {
	sol := solver{}
	sol.w = getNextInt(scanner)
	sol.h = getNextInt(scanner)
	if sol.w == 0 && sol.h == 0 {
		return false
	}
	sol.land = makeInts(sol.h, sol.w)
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			sol.land[y][x] = getNextInt(scanner)
		}
	}
	ans := 0
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			if sol.land[y][x] == 0 {
				continue
			}
			ans++
			sol.dfs(y, x)
		}
	}
	fmt.Fprintln(writer, ans)
	return true
}

type solver struct {
	w, h int
	land [][]int
}

func (sol *solver) dfs(y, x int) {
	if y < 0 {
		return
	}
	if y >= sol.h {
		return
	}
	if x < 0 {
		return
	}
	if x >= sol.w {
		return
	}
	if sol.land[y][x] == 0 {
		return
	}
	sol.land[y][x] = 0
	dy := [8]int{-1, -1, -1, 0, 0, 1, 1, 1}
	dx := [8]int{-1, 0, 1, -1, 1, -1, 0, 1}
	for i := 0; i < 8; i++ {
		sol.dfs(y+dy[i], x+dx[i])
	}
}
func makeInts(h, w int) [][]int {
	index := make([][]int, h, h)
	data := make([]int, h*w, h*w)
	for i := 0; i < h; i++ {
		index[i] = data[i*w : (i+1)*w]
	}
	return index
}

C++: /* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   main.cpp                                           :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: monoue <marvin@student.42.fr>              +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/04/22 12:30:15 by monoue            #+#    #+#             */
/*   Updated: 2020/05/05 08:55:10 by monoue           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include <bits/stdc++.h>

/* #include <boost/multi_array.hpp> */
/* #include <boost/optional.hpp> */
/* #include <boost/range/irange.hpp> */
/* #include <boost/range/algorithm.hpp> */
/* #include <boost/range/adaptors.hpp> */
/* #include <boost/multiprecision/cpp_int.hpp> */
/* #include <boost/algorithm/string/classification.hpp> // is_any_of */
/* #include <boost/algorithm/string/split.hpp> */
/* #include <boost/algorithm/string/join.hpp> */
/* #include <boost/algorithm/string/replace.hpp> */
/* #include <boost/math/tools/minima.hpp> */
/* namespace adaptor = boost::adaptors; */
/* using boost::math::tools::brent_find_minima; */
/* using boost::irange; */
/* using boost::algorithm::join; */
/* using boost::algorithm::split; */
/* using boost::algorithm::replace_all; */
/* using boost::multiprecision::cpp_int; */

using namespace std;

#define	int	long long
#define MOD 1000000007
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define rrep(i, n) for (int i = (n); i >= 0; --i)

typedef long long 			ll;
typedef vector<int>			VI;
typedef vector<vector<int>>	VVI;
typedef pair<int, int>		PII;

// TOP
int	h, w;

VVI	field;

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

void	dfs(int y, int x)
{
	field[y][x] = 0;
	int	ny, nx;
	rep(dir, 8)
	{
		ny = y + dy[dir];
		nx = x + dx[dir];
		if (ny < 0 || ny >= h || nx < 0 || nx >= w)
			continue;
		if (field[ny][nx] == 0)
			continue;
		dfs(ny, nx);
	}
}

void	Main()
{
	while (cin >> w >> h)
	{
		if (w == 0 && h == 0)
			break;
		field.assign(h, VI(w));
		rep(y, h)
		{
			rep(x, w)
					cin >> field[y][x];
		}
		int count;
		count = 0;
		rep(y, h)
		{
			rep(x, w)
			{
				if (field[y][x] == 0)
					continue;
				dfs(y, x);
				count++;
			}
		}
		cout << count << endl;
	}
}
// END

int32_t	main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	Main();
}

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

int w,h;
int islID;
int mp[52][52], island[52][52];
void dfs(int x, int y){
  if (mp[x][y]==0 || island[x][y]) return;
  island[x][y] = islID;
  for (int dx = -1; dx<=1; dx++){
    for (int dy= -1; dy<=1; dy++){
      if (dx==0 && dy==0) continue;
      dfs(x+dx, y+dy);
    }
  }
}

int main(void){  
  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 >> mp[j+1][i+1];
        island[j+1][i+1] = 0;
      }
    }
    islID = 0;
    for (int i=1; i<=h; i++){
      for (int j=1; j<=w; j++){
        if (mp[j][i] && !island[j][i]){
          islID++; 
          dfs(j, i);
        }
//        cout << island[j][i] << " ";
      }
//      cout << endl;
    }
    cout << islID << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
int dx[] = {1,1,0,-1,-1,-1,0,1};
int dy[] = {0,1,1,1,0,-1,-1,-1};
int c[51][51];
int main()
{

	int w, h;

	while (cin >> w && cin >> h && w != 0 && h != 0)
	{
		for (int i = 1; i < h + 1; i++)
		{
			for (int j = 1; j < w + 1; j++)
			{
				int tmp;
				cin >> tmp;
				if (tmp == 0)
				{
					c[i][j] = -1;
				}
				else
				{
					c[i][j] = 0;
				}
			}
		}

		int count = 0;
		queue<pair<int,int> > q;
		for (int i = 1; i < h + 1; i++)
		{
			for (int j = 1; j < w + 1; j++)
			{
				if (c[i][j] != 0)continue;
				q.push(make_pair(i,j));
				c[i][j] = 1;
				while (q.size() > 0)
				{
					pair<int, int> p = q.front();
					q.pop();
					int y = p.first;
					int x = p.second;

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

						if (nx < 1 || ny < 1 || nx > w || ny > h)continue;
						if (c[ny][nx] != 0)continue;
						q.push(make_pair(ny, nx));
						c[ny][nx] = 1;
					}
				}
				count++;
			}
		}

		cout << count << endl;


	}

	return 0;
}