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++: #if 0

#endif

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

int W, H;
int x[8] = {1,0,-1,0,1,1,-1,-1};
int y[8] = {0,-1,0,1,1,-1,1,-1};

bool in_map(int h, int w) {
  return (1 <= h && h <= H && 1 <= w && w <= W);
}

int main() {
  while(cin >> W >> H && W > 0) {
    int M[55][55];
    for (int h = 1; h <= H; h++) {
      for (int w = 1; w <= W; w++)
        cin >> M[h][w];
    }
    queue<pair<int,int>> Q;
    int ans = 0;
    for (int sh = 1; sh <= H; sh++) {
      for (int sw = 1; sw <= W; sw++) {
        if (M[sh][sw] == 1) {
          ans++;
          Q.push(make_pair(sh,sw));
          M[sh][sw] = 0;
          while (!Q.empty()) {
            pair<int,int> p = Q.front();
            Q.pop();
            int h = p.first; int w = p.second;
            for (int i = 0; i < 8; i++) {
              int nh = h+y[i]; int nw = w+x[i];
              if (in_map(nh, nw) && M[nh][nw] == 1) {
                Q.push(make_pair(nh, nw));
                M[nh][nw] = 0;
              }
            }
          }
        }
      }
    }

    cout << ans << endl;
  }
}

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

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;

int c[50][50] = {};

void dfs(int x, int y, int h, int w) {
	if (c[y][x] == 0) {
		return;
	}
	c[y][x] = 0;
	if (x + 1 <= w - 1) {
		dfs(x + 1, y, h, w);
	}
	if (x - 1 >= 0) {
		dfs(x - 1, y, h, w);
	}
	if (y + 1 <= h - 1) {
		dfs(x, y + 1, h, w);
	}
	if (y - 1 >= 0) {
		dfs(x,y - 1, h, w);
	}
	if (x + 1 <= w - 1 && y + 1 <= h - 1) {
		dfs(x + 1, y + 1, h, w);
	}
	if (x + 1 <= w - 1 && y - 1 >= 0) {
		dfs(x + 1, y - 1, h, w);
	}
	if (x - 1 >= 0 && y + 1 <= h - 1) {
		dfs(x - 1, y + 1, h, w);
	}
	if (x - 1 >= 0 && y - 1 >= 0) {
		dfs(x - 1, y - 1, h, w);
	}
	return;
}

int main(void) {
	
	while (1) {
		int h, w;
		int count = 0;

		cin >> w >> h;
		if (h == 0) {
			break;
		}
		

		FOR(i, 0, h - 1) {
			FOR(t, 0, w - 1) {
				cin >> c[i][t];
			}
		}
		FOR(i, 0, h - 1) {
			FOR(t, 0, w - 1) {
				if (c[i][t] == 0) {
					continue;
				}
				
				dfs(t, i, h, w);
				count++;
			}
		}
		cout << count << endl;
	}

}

C++: /************************************
 * ???????????¢?´¢??§??¶?????°?????°??????????????°?????? *
 ************************************/

#include <iostream>
#include <queue>
#include <map>

#define LAND '1'  //??? char???
#define SEA  '0'   //??? char???

using namespace std;

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

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

bool input(vector< vector<char> > &m);
void delete_island(vector< vector< char > > &m, int x, int y);
void output(vector< vector< char> > m);


int main(){
  int w, h;
    
  while(cin >> w >> h, w && h){
    vector< vector< char > > m(h+2, vector<char>(w+2));
    input(m);
    
    int island = 0;
    for(int y = 0; y < m.size(); y++){
      for(int x = 0; x < m[y].size(); x++){
	if(m[y][x] == LAND){
	  delete_island(m,x,y);
	  island++;
	}
      }
    }
    cout << island << endl;
  }
}


bool input(vector< vector<char> > &m){
  for(int y = 0; y < m.size(); y++){
    for(int x = 0; x < m[y].size(); x++){
      if(y == 0 || x == 0 ||
	 y == m.size()-1 || x == m[y].size()-1){
	m[y][x] = SEA;
      }else{
	if(!(cin >> m[y][x])) return false;
      }
    }
  }
  return true;
}


 void delete_island(vector< vector< char > > &m, int x, int y){
   queue< pair< int, int > > q;
   q.push(make_pair(x,y));

   while(!(q.empty())){
     pair<int, int> cur = q.front();
     q.pop();
     if(m[cur.second][cur.first] == LAND){
       m[cur.second][cur.first] = SEA;
       for(int i = 0; i < sizeof(dx)/sizeof(int); i++){
	 q.push(make_pair(cur.first+dx[i],cur.second+dy[i]));
       }
     }
   }
}

void output(vector< vector< char> > m){
  for(int y = 0; y < m.size()-1; y++){
    for(int x = 0; x < m[y].size()-1; x++){
      cout << m[y][x] << " ";
    }
    cout << endl;
  }
  cout << endl;
}

C++: #include<bits/stdc++.h>
typedef long long ll;
typedef long double ld;
using namespace std;
ll H, W;
ll field[110][110];
ll dx[8] = { 0, 1, 0,-1, 1, 1,-1,-1 };
ll dy[8] = { 1, 0,-1, 0, 1,-1, 1,-1 };
void dfs(ll y, ll x) {
	field[y][x] = 0;
	for (ll i = 0; i < 8; i++) {
		ll ny = y + dy[i];
		ll nx = x + dx[i];
		if (nx >= 0 && nx < H && ny >= 0 && ny < W) {
			if (field[ny][nx] == 1)
				dfs(ny, nx);
		}
	}
}
int main() {
	while (cin >> H >> W) {
		if (H == 0 && W == 0) break;
		ll cnt = 0;
		for (ll i = 0; i < W; i++) {
			for (ll j = 0; j < H; j++) {
				cin >> field[i][j];
			}
		}
		for (ll y = 0; y < W; y++) {
			for (ll x = 0; x < H; x++) {
				if (field[y][x] == 1) {
					dfs(y, x);
					cnt++;
				}
			}
		}
		cout << cnt << endl;
	}
}

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

int M[52][52];

void fill(int y, int x){
	M[y][x] = 0;
	if(M[y-1][x]) fill(y-1,x);
	if(M[y+1][x]) fill(y+1,x);
	if(M[y][x-1]) fill(y,x-1);
	if(M[y][x+1]) fill(y,x+1);
	if(M[y-1][x-1]) fill(y-1,x-1);
	if(M[y+1][x-1]) fill(y+1,x-1);
	if(M[y-1][x+1]) fill(y-1,x+1);
	if(M[y+1][x+1]) fill(y+1,x+1);
}

main(){
	int w,h,c,i,j;
	while(cin>>w>>h,w){
		memset(M, 0, sizeof(M));
		c=0;
		for(i=1;i<=h;i++){
		for(j=1;j<=w;j++){
			cin >> M[i][j];
		}
		}
		for(i=1;i<=h;i++){
		for(j=1;j<=w;j++){
			if(!M[i][j]) continue;
			fill(i, j);
			c ++;
		}
		}
		
		cout << c << endl;
	}
}