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 <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, a, b) for (int i = a; i < b; ++i)
#define FORR(i, a, b) for (int i = b - 1; i >= a; --i)
#define SORT(v) sort(v.begin(), v.end())
#define SORTR(v) sort(v.rbegin(), v.rend())
#define REV(v) reverse(v.begin(), v.end())
#define ITER(itr, v) for (auto itr = v.begin(); itr != v.end(); ++itr)
#define LB(v, x) (lower_bound(v.begin(), v.end(), x) - v.begin())
#define UB(v, x) (upper_bound(v.begin(), v.end(), x) - v.begin())
#define SZ(v) (int)v.size()
using namespace std;
using ll = long long;
using P = pair<int, int>;

class Grid {
	int h, w;
	vector<vector<int>> c;
	const int di[8] = {1, 1, 0, -1, -1, -1, 0, 1};
	const int dj[8] = {0, 1, 1, 1, 0, -1, -1, -1};

public:
	Grid(int h, int w) : h(h), w(w), c(h, vector<int>(w)) {}
	void input() {
		REP(i, h) {
			REP(j, w) {
				cin >> c[i][j];
			}
		}
	}
	int dfs(int i, int j) {
		if (c[i][j] == 0) return 0;
		c[i][j] = 0;
		REP(k, 8) {
			int u = i + di[k];
			int v = j + dj[k];
			if (u >= 0 && u < h && v >= 0 && v < w) {
				dfs(u, v);
			}
		}
		return 1;
	}
	int ans() {
		int res = 0;
		REP(i, h) {
			REP(j, w) {
				res += dfs(i, j);
			}
		}
		return res;
	}
};

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	while (true) {
		int h, w;
		cin >> w >> h;
		if (h == 0 && w == 0) break;
		Grid grid(h, w);
		grid.input();
		cout << grid.ans() << endl;
	}

	return 0;
}

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

using namespace std;

typedef vector<int> vi;
typedef pair<int,int> pii;

#define dump(x)  cerr << #x << " = " << (x) << endl
#define rep(i,n) for(int i=0;i<(n);i++)
#define pb push_back

int map[60][60]={};
bool visited[60][60]={false};
int w,h;

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

void dfs(int x,int y){
    if(x<0 || x>=w || y<0 || y>=h)return ;
    if(map[y][x]==0)return ;
    if(visited[y][x]==true)return ;
    
    visited[y][x]=true;
    rep(i,8){
        dfs(x+dx[i],y+dy[i]);
    }
}

int main(){
    while(cin>>w>>h){
        rep(i,60)rep(j,60)visited[i][j]=false;
        int c=0;
        if(w==0 || h==0)break;
        
        rep(i,h) rep(j,w) cin>>map[i][j];
        
        rep(i,h){
            rep(j,w){
                if(visited[i][j]==false && map[i][j]==1){
                    dfs(j,i);
                    c++;
                }
            }
        }
        cout<<c<<endl;
        
    }
    
    return 0;
}

C++: #include <iostream>

using namespace std;
int c[51][51];
int w ,h;

bool input(){
	cin >> h >> w;
	if(w==0) return false;
	for(int i = 0;i <51;i++){
		for(int j = 0;j <51 ;j++){
			c[i][j] = 2;
		}
	}

	for(int i = 0;i < w ;i++){
		for(int j = 0; j < h ;j++){
			cin >> c[i][j];
//			cout <<c[i][j];
		}
	}
	return true;
}

void dfs(int x,int y){
	c[x][y] = 0;
	for(int i = -1; i <=1 ;i++){
		for(int j = -1; j <=1 ;j++){
			int nx = x + i;
			int ny = y + j;
//			cout <<nx << ' ' << ny << endl;
			if(0 <= nx && nx < w && 0 <= ny && ny < h && c[nx][ny] == 1)dfs(nx,ny);
		}
	}
}

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

int main(){
	while(input())solve();
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <queue>

using namespace std;

struct node{
  int x,y;
};

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

int main(){
  int w,h,i,j,k,ans=0;
  while(1){
    queue<node> que;
    scanf("%d %d",&w, &h);
    if(w+h == 0)break;
    int c[h][w];
    ans = 0;
    node now,next,to;
    for(i=0;i<h;i++){
      for(j=0;j<w;j++)scanf("%d",&c[i][j]);
    }
    for(i=0;i<h;i++){
      for(j=0;j<w;j++){
        if(c[i][j]){
          ++ans;
          now.x = j; now.y = i;
          que.push(now);
          while(!que.empty()){
            next = que.front();
            c[next.y][next.x] = 0;
            que.pop();
            for(k=0;k<8;k++){
              to.x = next.x + dx[k];
              to.y = next.y + dy[k];
              if(to.x<0 || to.x >=w || to.y<0 || to.y >=h)continue;
              if(c[to.y][to.x]){
                que.push(to);
              }
            }
          }
        }
      }
    }
    printf("%d",ans);
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
using i64 = int_fast64_t;
#define rep(i, N) for(int i = 0; i < N; i++)
#define all(v) v.begin(), v.end()
#define eb emplace_back
#define Cout(s) cout << s << endl
string Yes(bool b) {if(b){return "Yes";} else {return "No";}}
string YES(bool b) {if(b){return "YES";} else {return "NO";}}

int main(){
    int W, H;
    while(cin >> W >> H, W != 0){

        vector<vector<int>> mp(H, vector<int>(W));
        rep(h, H) rep(w, W) cin >> mp[h][w];

        const int dy[8] = {1,1,-1,-1,1,-1,0,0};
        const int dx[8] = {1,0,-1,1,-1,0,-1,1};
        vector<vector<bool>> visited(H, vector<bool>(W, false));

        auto dfs = [&](auto&& dfs_, int y, int x) -> void {
            visited[y][x] = true;

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

                if(ny < 0 || ny >= H || nx < 0 || nx >= W) continue;
                if(visited[ny][nx] || mp[ny][nx] == 0) continue;

                dfs_(dfs_, ny, nx);
            }
        };

        int ans = 0;
        rep(h, H) rep(w, W){
            if(mp[h][w] == 1 && visited[h][w] == false){
                ans++;
                dfs(dfs, h, w);
            }
        }

        cout << ans << endl;
    }
}