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 <algorithm>
#include <cstdio>

using namespace std;

#define int long long
#define dotimes(i, n) for (int i = 0; i < (n); i++)

int rint() {
  int n;
  scanf("%lld", &n);
  return n;
}

int w, h;
int c[50][50], d[50][50];

bool rec(int i, int j) {
  if (!c[i][j] || d[i][j])
    return false;
  d[i][j] = true;
  for (int y = -1; y <= 1; y++)
    for (int x = -1; x <= 1; x++)
      if ((x || y) && 0 <= i+y && i+y < h && 0 <= j+x && j+x < w)
        rec(i+y, j+x);
  return true;
};

signed main() {
  for (;;) {
    w = rint();
    h = rint();
    if (!w && !h)
      return 0;
    dotimes(i, h)
      dotimes(j, w) {
        c[i][j] = rint();
        d[i][j] = 0;
      }
    int r = 0;
    dotimes(i, h)
      dotimes(j, w)
        if (rec(i, j))
          r++;
    printf("%lld\n", r);
  }
}

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

using namespace std;

inline bool inRange(int a, int x, int b) {
    return a <= x && x < b;
}

void fill(vector<vector<int> > &v, int r, int c) {
    v[r][c] = 0;
    for(int dr = -1; dr <= 1; ++dr) {
        for(int dc = -1; dc <= 1; ++dc) {
            int nr = r + dr;
            int nc = c + dc;
            if(inRange(0, nr, v.size()) && inRange(0, nc, v[0].size()) && v[nr][nc]) {
                fill(v, nr, nc);
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(0);

    while(true) {
        int C, R;
        cin >> C >> R;
        if(!C && !R) break;

        vector<vector<int> > v(R, vector<int>(C));
        for(int i = 0; i < R; ++i) 
            for(int j = 0; j < C; ++j)
                cin >> v[i][j];

        int cnt = 0;
        for(int r = 0; r < R; ++r) {
            for(int c = 0; c < C; ++c) {
                if(v[r][c]) {
                    ++cnt;
                    fill(v, r, c);
                }
            }
        }

        cout << cnt << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
int dx[8]={0,1,1,1,0,-1,-1,-1};
int dy[8]={-1,-1,0,1,1,1,0,-1};
int main()
{
	int n,m;
	while(cin>>n>>m,n) 
	{
		int f[m][n];
		for(int i = 0; i < m; ++i)
		{
			for(int j = 0; j < n; ++j)
			{
				cin>>f[i][j];
			}
		}

		int ans=0;
		for(int i = 0; i < m; ++i)
		{
			for(int j = 0; j < n; ++j)
			{
				if(f[i][j]==1)
				{
					ans++;
					queue<int> xs,ys;
					xs.push(j); ys.push(i);
					while(!xs.empty()) 
					{
						int x=xs.front(),y=ys.front();
						xs.pop(); ys.pop();
						f[y][x]=0;
						for(int k = 0; k < 8; ++k)
						{
							int nx=x+dx[k],ny=y+dy[k];
							if(0<=nx&&nx<n&&0<=y&&y<m&&f[ny][nx]==1)
							{
								xs.push(nx); ys.push(ny);
							}
						}
					}
				}
			}
		}
		cout<<ans<<endl;
	}
  return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;
typedef long long int ll;
vector<vector<int>>v;
int w,h;

int dh[8] = {1,1,0,-1,-1,-1,0,1};
int dw[8] = {0,1,1,1,0,-1,-1,-1};

void dfs(int i, int j, int num)
{
    v[i][j] = 0;
    for(int k = 0; k < 8; k++)
    {
        int ni = i + dh[k];
        int nj = j + dw[k];
        if(ni >= h || ni < 0 || nj >= w || nj < 0) continue;
        if(!v[ni][nj]) continue;
        dfs(ni,nj,num);
    }
}

int main()
{
    while(cin >> w >> h)
    {
        if(w == 0 && h == 0) break;
        v.resize(h);
        for(int i = 0; i < h; i++)
        {
            v[i].resize(w);
            for(int j = 0; j < w; j++) cin >> v[i][j];
        }
        int num = 0;
        for(int i = 0; i < h; i++) for(int j = 0; j < w; j++) if(v[i][j]) num++, dfs(i,j,num);
        cout << num << endl;
    }
}

C++: #include <iostream>

using namespace std;

// 0: 海, 1: 陸
int board[50][50] = {{0}};

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

bool DFS(int i, int j, int w, int h) {
  if (i < 0 || i >= h || j < 0 || j >= w) return false;
  if (!board[i][j]) return false;

  board[i][j] = 0;
  for (int d = 0; d < 8; ++d)
    DFS(i + dy[d], j + dx[d], w, h);

  return true;
}

int main() {
  for (;;) {
    int w, h;
    cin >> w >> h;
    if (w == 0 && h == 0) break;

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

    int ans = 0;
    for (int i = 0; i < h; ++i) {
      for (int j = 0; j < w; ++j) {
        if (DFS(i, j, w, h)) ++ans;
      }
    }
    cout << ans << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#define rep(i,l,n) for(lint i=l;i<n;i++)
#define rer(i,l,n) for(lint i=l;i<=n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define pb(a) push_back(a)
#define mk(a,b) make_pair(a,b)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<lint> vli;
typedef vector<vi> vvi;
typedef pair<int, int> pii;

int w, h;
char s[55][55] = {};
int dy[8] = { 1, 1, 1, 0, 0, -1, -1, -1 };
int dx[8] = { -1, 0, 1, -1, 1, -1, 0, 1 };
int f[55][55] = {};

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

int main(){
	while (1){
		cin >> w >> h;
		if (w == 0 && h == 0) break;
		rep(i, 0, h){
			rep(j, 0, w){
				cin >> s[i][j];
			}
		}
		rep(i, 0, 55){
			rep(j, 0, 55){
				f[i][j] = 0;
			}
		}
		int c = 0;
		rep(i, 0, h){
			rep(j, 0, w){
				if (s[i][j] == '1' && f[i][j]==0){
					dfs(i, j);
					c++;
				}
			}
		}
		o(c);
	}
}