Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

C++: #include<stdio.h>
#include<string>
#include<iostream>
using namespace std;
int a[55][55]={};
int w,h;
void dfs(int y,int x){
  a[y][x]=0;
  int dy[8]={-1,-1,-1,0,0,1,1,1};
  int dx[8]={-1,0,1,-1,1,-1,0,1};
  for(int i=0;i<8;i++){
    int ny=y+dy[i];
    int nx=x+dx[i];
    if(nx<0||ny<0||nx>=w||ny>=h)continue;
    if(a[ny][nx]==0)continue;
    dfs(ny,nx);
  }
}
int main(){
  while(1){
    int ans=0;
    cin>>w>>h;
    if(w==0&&h==0)break;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin>>a[i][j];
      }
    }
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	if(a[i][j]==0)continue;
	ans++;
	dfs(i,j);
      }
    }
    cout<<ans<<endl;
  }
}

C++: #include<iostream>
using namespace std;
int ans;
int map[100][100];
void dfs(int x,int y,int w,int h);
int dx[8] = {1,1,0,-1,-1,-1,0,1},dy[8] = {0,1,1,1,0,-1,-1,-1};

int main(){
  int w,h;
  while(cin>>w>>h){
    ans=0;
    if(w == 0 && h == 0)break;
    for(int i = 0;i<h;i++)
      for(int j = 0;j<w;j++) 
	cin>>map[i][j];
    for(int i = 0;i<h;i++)
      for(int j = 0;j<w;j++){
	if(map[i][j] == 1){
	  ans++;
	  dfs(i,j,w,h);
	  // for(int a=0;a<h;a++){
	  //   for(int b=0;b<w;b++) cout<<map[a][b];
	  // cout<<endl;
	  // }
	  // cout<<endl;
	}
      }
    cout<<ans<<endl;
  }
  return 0;
}

void dfs(int x,int y,int w,int h){
  //cout<<"LK+LKJ"<<endl;
  int nx,ny;
  for(int i = 0;i<8;i++){
    nx = x+dx[i]; ny = y+dy[i];
    if(nx>=0 && nx<w && ny>=0 && ny<h && map[ny][nx] == 1){
      map[ny][nx] = 0;
      dfs(nx,ny,w,h);
    }
  }
}

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

int w,h;
int filed[51][51];

void dfs(int x,int y){
  filexd[x][y]=0;
  for(int dx=-1;dx<=1;dx++){
    for(int dy=-1;dy<=1;dy++){
      int nx=x+dx,ny=y+dy;
      if(0<=nx&&nx<h&&0<=ny&&ny<w&&filed[nx][ny]==1)dfs(nx,ny);
    }
  }
}

void solve(){
  int res=0;
  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      if(filed[i][j]==1){
	dfs(i,j);
	res++;
      }
    }
  }
  cout<<res<<endl;
}

int main(){
  while(1){
    cin>>w>>h;
    if(w+h==0)break;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin>>filed[i][j];
      }
    }
    solve();
  }
  return 0;
}

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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#define ull unsigned long long
#define ld long double

template <class T>
using V = vector<T>;
template <class T>
using VV = V<V<T>>;

#define rep2(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) rep2(i, 0, n)
#define rep1(i, n) rep1(i, 1, n + 1)

// #define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
// #define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()  //

#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

// 総数を1000000007（素数）で割った余り
const long long mod = 1e9 + 7;

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

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << std::fixed << std::setprecision(15);
    //    cout << std::setfill('0') << std::setw(2);

    while(1) {
        int w,h;
        cin >>w>>h;
        if(w == 0 && h == 0) break;
        VV<int> a(h);
        rep(i,h)rep(j,w) {
            int inn;
            cin >> inn;
            a[i].push_back(inn);
        }
        auto dfs = [&](auto self, int x, int y) {
            if(x<0||y<0||x>=w||y>=h) return;
            if(a[y][x] == 0) return;
            a[y][x] = 0;
            rep(i, 8) {
                self(self, x+dx[i], y+dy[i]);
            }
        };
        int ans = 0;
        rep(i,h)rep(j,w) {
            if(a[i][j] == 1) {
                ans++;
                dfs(dfs, j,i);
            }
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;
int w,h;
int in[100][100];
bool seen[100][100];
int ans =0;
bool flag = false;

void solve(int i,int j){
    cout << i << " " << j << endl;
    if(i < 0 || j < 0 || i >= h || j >= w){
        return;
    }
    if(seen[i][j]){
        return;
    }
    if(in[i][j] == 0){
        return;
    }
    seen[i][j] = true;
    solve(i-1,j-1);
    solve(i-1,j);
    solve(i-1,j+1);
    solve(i,j-1);
    solve(i,j+1);
    solve(i+1,j-1);
    solve(i+1,j);
    solve(i+1,j+1);

}
int main(){
    cin >> w >> h;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin >> in[i][j];
        }
    }
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(seen[i][j] == true || in[i][j] == 0){
            }
            else{
                solve(i,j);
                ans++;
            }
            
        }
    }
    cout << ans << endl;
    return 0;
}