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>
using namespace std;
#define inf 1000000000
#define INF 1000000000000000
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S second
#define PB push_back
#define int ll
int w,h;

void f(int c[100][100],bool b[100][100],int y,int x){

  if(y<0||x<0||y>h||x>w||!c[y][x]||b[y][x]) return;
  b[y][x]=true;
  f(c,b,y+1,x);
  f(c,b,y-1,x);
  f(c,b,y,x+1);
  f(c,b,y,x-1);
  f(c,b,y+1,x+1);
  f(c,b,y+1,x-1);
  f(c,b,y-1,x+1);
  f(c,b,y-1,x-1);
}



signed main(){
  while(1){
    
    cin>>w>>h;
    if(w==0) break;

    int c[100][100]={};
    rep(i,h){
      rep(j,w){
        cin>>c[i][j];
      }
    }

    bool b[100][100]={};

    int s=0;

    rep(i,h){
      rep(j,w){
        if(c[i][j]&&!b[i][j]){
          f(c,b,i,j);
          s++;
        }
      }
    }

    cout<<s<<endl;
  }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <cmath>
#include <tuple>
#include <cstdio>
#include <bitset>
#include <sstream>
#include <iterator>
#include <numeric>
#include <map>
#include <cstring>
#include <set>
#include <functional>
#include <iomanip>

using namespace std;

#define DEBUG_ //!!提出時にコメントアウト!!
#ifdef DEBUG_
	#define dump(x)  cerr << #x << " = " << (x) << endl;
#else
	#define dump(x)  ;
#endif

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back

//#define int long long

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

template <typename T>
std::string printVector(const std::vector<T> &data)
{
    std::stringstream ss;
    std::ostream_iterator<T> out_it(ss, ", ");
    ss << "[";
    std::copy(data.begin(), data.end() - 1, out_it);
    ss << data.back() << "]";
    return ss.str();
}

const int MOD = 1e9+7;
const LL LINF = 1001002003004005006ll;
const int INF = 1001001001;

int masu[100][100] = {};
int used[100][100] = {};
int w,h;
int dx[8] = {-1,-1,-1,0,0,1,1,1};
int dy[8] = {-1,0,1,-1,1,-1,0,1};

void dfs(int x, int y){
    used[x][y] = 1;
    REP(i,8){
        int tx = dx[i] + x;
        int ty = dy[i] + y;
        if(0 <= tx && tx < h && 0 <= ty && ty < w && used[tx][ty] != 1 && masu[tx][ty] == 1){
            dfs(tx,ty);
        }
    }
}

signed main(int argc, char const *argv[])
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    while(1){
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        REP(i,h) REP(j,w) {
            cin >> masu[i][j];
            used[i][j] = 0;
        }
        int ans = 0;
        REP(i,h)  REP(j,w)  {
            if(!used[i][j] && masu[i][j] == 1){
                dfs(i,j);
                ans++;
            }
        }
        cout << ans << endl;
    }

}

C++: #include <iostream>
#include <queue>
#include <map>

using namespace std;

typedef pair<int, int> P;

int main() {
    int w, h;
    int dx[] = {0, 1, 0, -1, 1, 1, -1, -1};
    int dy[] = {1, 0, -1, 0, 1, -1, 1, -1};
    int map[50][50];
    while (true) {
        int count = 0;
        cin >> w >> h;
        if (w == 0) {
            return 0;
        }
        for (int y=0; y<h; y++) {
            for (int x=0; x<w; x++) {
                cin >> map[x][y];
            }
        }
        for (int y0=0; y0<h; y0++) {
            for (int x0=0; x0<w; x0++) {
                queue<P> q;
                if (map[x0][y0] == 0) {
                    continue;
                }
                count++;
                q.push(P(x0, y0));
                while (!q.empty()) {
                    int x = q.front().first;
                    int y = q.front().second;
                    q.pop();
                    for (int i=0; i<8; i++) {
                        int nx = x+dx[i];
                        int ny = y+dy[i];
                        if (nx < 0 || w <= nx || ny < 0 || h <= ny) {
                            continue;
                        }
                        if (map[nx][ny] == 0) {
                            continue;
                        }
                        map[nx][ny] = 0;
                        q.push(P(nx, ny));
                    }
                }
            }
        }
        cout << count << endl;
    }
}

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

int w,h;
int maze[100][100];

void solve(int x,int y){

  if(x < 0 || y < 0 || x == w || y == h) return;
  if(!maze[y][x]) return;

  maze[y][x] = 0;

  for(int i=-1;i<2;i++){
    for(int j=-1;j<2;j++){
      solve(x+i,y+j);
    }
  }

}
int main(){

  while(true){
    cin >> w >> h;
    if(!w && !h) break;

    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++) cin >> maze[i][j];
    }

    int ans = 0;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	if(maze[i][j] == 1) solve(j,i), ans++;
      }
    }

    cout << ans << endl;

  }
}

C++: // include
#include <iostream>

// typedef
typedef unsigned long long ull;
typedef unsigned int uint;

// macro
#define REP(index, num) for (auto index = 0; index < num; index++)
#define REP1(index, num) for (auto index = 1; index <= num; index++)

#define MAX_NUM 60

// using namespace 
using namespace std;

const int ExistIsland(const int inX, const int inY);

// global
int W, H;
int c[MAX_NUM][MAX_NUM] = { 0 };

int main()
{
  while (1)
  {
    cin >> W >> H;

    // 入力が 0 0 なら終了
    if (W * H == 0)
      break;

    REP(hId, H)
      REP(wId, W)
      cin >> c[wId][hId];

    // 深さ優先探索
    int count = 0;
    REP(hId, H)
      REP(wId, W)
      count += ExistIsland(wId, hId);

    cout << count << endl;
  } 
}

const int ExistIsland(const int inX, const int inY)
{
  if (inX < 0 || W <= inX) return 0;
  if (inY < 0 || H <= inY) return 0;

  if (c[inX][inY] == 0)
    return 0;
  else
    c[inX][inY] = 0;

  //bool existFlag = true;

  // 周りに移動
  ExistIsland(inX + 1, inY);
  ExistIsland(inX + 1, inY + 1);
  ExistIsland(inX, inY + 1);
  ExistIsland(inX - 1, inY + 1);
  ExistIsland(inX - 1, inY);
  ExistIsland(inX - 1, inY - 1);
  ExistIsland(inX, inY - 1);
  ExistIsland(inX + 1, inY - 1);

  return 1;
}