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>
using namespace std;
#define rep(i, n) for(int i = 0, i##_len = (n); i < i##_len; ++i)
#define rep2(i, x, n) for(int i = x, i##_len = (n); i < i##_len; ++i)
#define all(n) begin(n), end(n)
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<string>;
using vc = vector<char>;
using vb = vector<bool>;
using vd = vector<double>;
vi dir = {-1, 0, 1, 0, -1, -1, 1, 1, -1};

void solve(int h, int w) {
  vector<vi> g(h + 2, vi(w + 2, -1));
  rep2(i, 1, h + 1) rep2(j, 1, w + 1) {
    int c;
    cin >> c;
    if(c == 1) g[i][j] = 0;
  }
  int ans = 0;
  rep2(a, 1, h + 1) rep2(b, 1, w + 1) {
    if(g[a][b] != 0) continue;
    ans++;
    g[a][b] = ans;
    stack<pair<int, int>> st;
    st.push(P(a, b));
    while(!st.empty()) {
      int i = st.top().first;
      int j = st.top().second;
      st.pop();
      rep(k, 8) {
        int ni = i + dir[k];
        int nj = j + dir[k + 1];
        if(g[ni][nj] != 0) continue;
        g[ni][nj] = g[i][j];
        st.push(P(ni, nj));
      }
    }
  }
  cout << ans << endl;
}

int main() {
  while(true) {
    int h, w;
    cin >> w >> h;
    if(h == 0 && w == 0) break;
    solve(h, w);
  }
}

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

int map[20][20];

typedef pair<int, int> pxy;

int h, w, ans = 0;

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

void bfs(int sx, int sy)
{
  queue<pxy> q;
  q.push(pxy(sx, sy)); 
  while(!q.empty()){
    int x, y;
    x = q.front().first;
    y = q.front().second;
    q.pop();
    if(map[x][y]){
      map[x][y] = 0;
      for(int i = 0; i < 8; i++){
	int next_x = x + dx[i], next_y = y + dy[i];
	if(map[next_x][next_y]){
	  q.push(pxy(next_x, next_y));
	}
      }
    }
  }
}

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

C++: #include <cstdio>
#include <cstring>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <set>
using namespace std;

#define rep(i,n) for(int i=0;i<(n);i++)
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define dbg(x) cout<<#x"="<<x<<endl

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<pii, int> ppi;

#define INF 1000000000
#define SIZE 51

bool f[SIZE][SIZE]; //true=land (1)
int w,h;

void wfs(int i, int j){
  //width-first search
  int d[]={1,0,-1};
  rep(di,3){
    int ni=i+d[di];
    if(ni<0 || ni>=h) continue;
    rep(dj,3){
      int nj=j+d[dj];
      if(nj<0 || nj>=w) continue;
      if(f[ni][nj]){
	f[ni][nj]=false;
	wfs(ni,nj);
      }
    }
  }
}

int main(){
  while(true){
    cin >>w>>h;
    if(w==0&&h==0) break;
    
    rep(i,h){
      rep(j,w){
	int d;
	scanf("%d", &d);
	if(d==0) f[i][j]=false;
	else  f[i][j]=true; //1=land
      }
    }

    int ans=0;
    rep(i,h){
      rep(j,w){
	if(f[i][j]){
	  ans++;
	  wfs(i,j);
	}
      }
    }

    cout << ans << endl;

  }
}

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

using namespace std;

int w,h;
int map[100][100];

void delIsland(int y,int x){

  queue<pair<int,int> > que;
  que.push(make_pair(y,x));


  int next[8][2] = {{0,1},{0,-1},{1,0},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1}};
  while(!que.empty()){
    pair<int,int> now  = que.front();
    que.pop();

    if(now.first<0 || now.first>=h || now.second<0 || now.second>=w || map[now.first][now.second]!=1){
      continue;
    }else{
      map[now.first][now.second] = 0;
    }


    for(int i=0;i<8;i++){
      int ny = now.first + next[i][0];
      int nx = now.second + next[i][1];
      que.push(make_pair(ny,nx));
    }
  }
}

int main(){
  cin>>w>>h;
  while(w!=0 && h!=0){
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
       cin>>map[i][j];
     }
   }

   int ans = 0;
   for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
     if(map[i][j] == 1){
       ans++;
       delIsland(i,j);
     }
   }
 }

 cout<<ans<<endl;
 cin>>w>>h;
}

return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<cstdlib>
#include<math.h>
#include<algorithm>
#include<string>
#include<vector>
#include<list>
#include<queue>
#include<stack>
#include<deque>
#include<set>
#include<map>
#define REP(i, N) for(ll i = 0; i < N; ++i)
#define FOR(i, a, b) for(ll i = a; i < b; ++i)
#define ALL(a) (a).begin(),(a).end()
#define pb push_back
#define INF 1000000000
#define MOD 1000000007
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
int qx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
int qy[8] = {0, 1, 1, 1, 0, -1, -1, -1};

vector<vector<int> > mp;
int w, h;


void hoge(int wo, int ho) {
	mp[wo][ho] = 0;
	REP(i, 8) {
		int nw = wo + qx[i];
		int nh = ho + qy[i];
		if(nw >= 0 && nw < w && nh >= 0 && nh < h && mp[nw][nh] == 1) hoge(nw, nh);
	}
}
int main(void) {
	while(true) {
	ll count = 0;
	cin>>w>>h;
		if(w == 0 && h == 0) return 0;
		swap(w, h);
	mp.resize(w);
	REP(i, w) mp[i].resize(h);
	REP(i, w) {
		REP(j, h) {
			cin>> mp[i][j];
		}
	}
	REP(i, w) {
		REP(j, h) {
			if(mp[i][j] == 1) {
				count++;
				hoge(i, j);
			}
		}
	}
	cout<<count<<endl;
}
}