Go: package main

import (
	"fmt"
)

func main() {
	var h, w int
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			return
		}
		matrix := make([][]int, h)
		Sean := make([][]bool, h)
		for i := 0; i < h; i++ {
			matrix[i] = make([]int, w)
			Sean[i] = make([]bool, w)
			for j := 0; j < w; j++ {
				fmt.Scan(&matrix[i][j])
			}
		}
		var count int
		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				if matrix[i][j] == 1 && Sean[i][j] == false {
					search(i, j, h, w, matrix, Sean)
					count++
				}
			}
		}
		fmt.Println(count)
	}
}
func search(x int, y int, h int, w int, matrix [][]int, Sean [][]bool) {
	if x < 0 || y < 0 || x >= h || y >= w || matrix[x][y] == 0 {
		return
	}
	if Sean[x][y] == true {
		return
	}

	Sean[x][y] = true

	search(x+1, y, h, w, matrix, Sean)
	search(x-1, y, h, w, matrix, Sean)
	search(x, y+1, h, w, matrix, Sean)
	search(x, y-1, h, w, matrix, Sean)
	search(x+1, y-1, h, w, matrix, Sean)
	search(x-1, y+1, h, w, matrix, Sean)
	search(x+1, y+1, h, w, matrix, Sean)
	search(x-1, y-1, h, w, matrix, Sean)
}

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

bool search(vector<vector<bool>>& isvisit, vector<vector<int>> c, int i, int j){
    if(!(i >= 0 && i < isvisit.size() && j >= 0 && j < isvisit[i].size())){
        return false;
    }else if(isvisit[i][j]){
        return false;
    }else{
        isvisit[i][j] = true;
        if(c[i][j] == 0) return false;

        for(int ii = -1; ii <= 1; ii += 2){
            search(isvisit, c, i+ii, j);
            search(isvisit, c, i, j+ii);
            search(isvisit, c, i+ii, j+ii);
            search(isvisit, c, i+ii, j-ii);
        }
        return true;
    }
}

int main(){
    int w, h;
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        vector<vector<int>> c(h, vector<int>(w));
        for(int i = 0; i < h; i++){
            for(int j = 0; j < w; j++) cin >> c[i][j];
        }
        int ans = 0;
        vector<vector<bool>> isvisit(h, vector<bool>(w, false));
        for(int i = 0; i < h; i++){
            for(int j = 0; j < w; j++){
                if(search(isvisit, c, i, j)) ans++;
            }
        }
        cout << ans << endl;
    }
    
    return 0;
}

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

int main() {
	int n;
	while (cin >> n, n) {

		vector<vector<int>>list(n, vector<int>(n, -1));
		int number;

		for (int i = 0;i < n;i++) {
			cin >> number;
			for (int j = 0;j < number;j++) {
				int codename;
				cin >> codename;
				list[i][codename - 1] = 1;
			}
		}//list[a][b]:a know b

		cin >> number;
		
		vector<int>ans(n,1);
		int leaked;
		for (int i = 0;i < number;i++) {
			cin >> leaked;
			for (int j = 0;j < n;j++) {
				if (list[j][leaked - 1] <= 0) ans[j] = 0;
			}
		}//who is imposible
		int sum = 0,telltale;

		for (int i = 0;i < n;i++) {
			sum += ans[i];
			if (ans[i] == 1) telltale = i + 1;
		}

		if (sum == 1)cout << telltale << endl;
		else cout << -1 << 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 <vector>
using namespace std;

void proc(vector<int> &maps,int p,int w,int h){
	if(maps[p]==1) maps[p]=2;
	else return;
	int x=p%w;
	int y=p/w;
	for(int i=-1;i<=1;++i){
		for(int j=-1;j<=1;++j){
			int nx=x+j;
			int ny=y+i;
			if(nx>=0&&ny>=0&&nx<w&&ny<h){
				proc(maps,nx+ny*w,w,h);
			}
		}
	}
}

int main(void){
	int w,h;
	while(cin>>w>>h,w&&h){
		vector<int> chizu(w*h);
		for(int i=0;i<h;++i){
			for(int j=0,a;j<w;++j){
				cin>>a;
				chizu[i*h+j]=a;
			}
		}
		int count = 0;
		for(int i=0;i<w*h;++i){
			if(chizu[i]==1){
				proc(chizu,i,w,h);
				++count;
			}
		}
		cout<<count<<endl;
	}
	return 0;
}

C++: 
#include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <bitset>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;
typedef long long ll;
typedef pair<int,int> pint;
typedef vector<int> vint;
typedef vector<pint> vpint;
#define mp make_pair
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for (int i=(n)-1;i>=0;i--)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define REPS(i,f,n) for (int i=(f)-1;i>=(n);i--)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, 1, -1};

int board[51][51];
int w, h;

void slove(void){
	int cnt = 0;
	queue<pint> q;
	rep(i, h){
		rep(j, w){
			if (board[i][j] == 1){
				q.push(mp(i, j));
				cnt++;
				/*
				rep(k, h){
					rep(l, w){
						printf("%d", board[k][l]);
					}
					printf("\n");
				}
				*/
				while(!q.empty()){
					pint now = q.front(); q.pop();
					rep(i, 8){
						int nowy = now.fi + dy[i];
						int nowx = now.se + dx[i];
						if (0 <= nowy && nowy <= h - 1 && 0 <= nowx && nowx <= w - 1 && board[nowy][nowx] == 1){
							board[nowy][nowx] = 0;
							q.push(make_pair(nowy, nowx));
						}
					}
				}
			}
		}
	}

	printf("%d\n", cnt);
	return;
}

void scan(int w, int h){
	rep(i, h) rep(j, w) cin >> board[i][j];

	slove();
	return;
}

int main(void){
	rep(i, 1000){
		cin >> w >> h;

		if (w == 0) break;
		scan(w, h);
	}
	return 0;
}

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

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

void dfs(int x, int y, vector<vector<bool> >& canGo){
  canGo[x][y] = false;
  for(int i = 0; i < 8; i++)
    if(canGo[x + dx[i]][y + dy[i]])
      dfs(x + dx[i], y + dy[i], canGo);
  return;
}


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

    int input;
    vector<vector<bool> > canGo(h + 2, vector<bool>(w + 2, false));
    for(int i = 1; i <= h; i++){
      for(int j = 1; j <= w; j++){
        cin >> input;
        if(input == 1){ canGo[i][j] = true; }
      }
    }

    int count = 0;
    for(int i = 1; i <= h; i++){
      for(int j = 1; j <= w; j++){
        if(canGo[i][j]){
          ++count;
          dfs(i, j, canGo);
        }
      }
    }

    cout << count << endl;
  }

  return 0;
}