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<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 <stdio.h>
#include <cmath>
#include <algorithm>
#include <stack>

using namespace std;

int map[50][50],width,height;
int dx[8] = {-1,0,1,-1,1,-1,0,1},dy[8] = {-1,-1,-1,0,0,1,1,1};

bool rangeCheck(int row,int col){
	if(row >= 0 && row <= height-1 && col >= 0 && col <= width-1)return true;
	else{
		return false;
	}
}

void erase(int row,int col){
	map[row][col] = 0;

	for(int i = 0; i < 8; i++){
		if(rangeCheck(row+dy[i],col+dx[i]) == true && map[row+dy[i]][col+dx[i]] == 1)erase(row+dy[i],col+dx[i]);
	}
}


int main(){

	int count;

	while(true){
		scanf("%d %d",&width,&height);
		if(width == 0 && height == 0)break;

		for(int i = 0; i < height; i++){
			for(int k = 0; k < width; k++){
				scanf("%d",&map[i][k]);
			}
		}

		count = 0;

		for(int row = 0; row < height; row++){
			for(int col = 0; col < width; col++){
				if(map[row][col] == 1){
					count++;
					erase(row,col);
				}
			}
		}


		printf("%d\n",count);

	}


	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <functional>
#include <iomanip>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <typeinfo>
#define PI 3.14159265359
#define INF 99999999
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(n) rep(i, n)
#define EPS 1e-10
#define pb push_back
#define mp make_pair
typedef long long ll;
using namespace std;
typedef pair<int, int> P;

bool isLeap(int y);
ll gcd(ll a, ll b);
ll lcm(ll a, ll b);
double distanceAB(double xa, double ya, double xb, double yb);
void trace(int A[], int N);

/*
class Target
{
public:
	vector <string> draw(int n)
	{

	}
};
*/


int w, h, c[50][50];
int dx[] = {-1, -1, -1, 0, 0, 1, 1, 1};
int dy[] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(int x, int y)
{
	c[y][x] = 0;
	
	rep(i, 8)
	{
		int nx = x + dx[i];
		int ny = y + dy[i];
		
		if (0<=nx && nx<w && 0<=ny && ny<h && c[ny][nx]==1)
		{
			dfs(nx, ny);
		}
	}
}


int main()
{
	while (cin >> w >> h, w || h)
	{
		int ans = 0;
		
		rep(i, h) rep(j, w) cin >> c[i][j];
		
		rep(i, h) rep(j, w)
		{
			if (c[i][j] == 1)
			{
				ans++;
				dfs(j, i);
			}
		}
		
		cout << ans << endl;
	}
	
	return 0;
}


bool isLeap(int y)
{
	return y % 400 == 0
						? true : y % 100 == 0
						? false : y % 4 == 0
						? true : false;
}

ll gcd(ll a, ll b)
{
	return (b > 0) ? gcd(b, a % b) : a;
}

ll lcm(ll a, ll b)
{
	return a / gcd(a, b) * b;
}

void trace(int A[], int N)
{
	REP(N)
	{
		if (i > 0) cout << " ";
		cout << A[i];
	}
	cout << endl;
}

double distanceAB(double xa, double ya, double xb, double yb)
{
	return sqrt((xb-xa)*(xb-xa) + (yb-ya)*(yb-ya));
}

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;
				
				
void del_island(int i,int j,vector<vector<int>> &v){	
	v[i][j] = 0;
	if(v[i-1][j] == 1){
		del_island(i-1,j,v);
	}
	if(v[i+1][j] == 1){
		del_island(i+1,j,v);
	}
	if(v[i][j-1] == 1){
		del_island(i,j-1,v);
	}
	if(v[i][j+1] == 1){
		del_island(i,j+1,v);
	}
	if(v[i-1][j-1] == 1){
		del_island(i-1,j-1,v);
	}
	if(v[i-1][j+1] == 1){
		del_island(i-1,j+1,v);
	}
	if(v[i+1][j-1] == 1){
		del_island(i+1,j-1,v);
	}
	if(v[i+1][j+1] == 1){
		del_island(i+1,j+1,v);
	}

}


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;
				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 = 1; i <= h ; i++){
			for(int j = 0 ; j <= w ; 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;
	}
}