Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

		route = make([][]int, h+2)
		route[0] = make([]int, w+2)
		for i := 1; i <= h; i++ {
			route[i] = make([]int, w+2)
			for j := 1; j <= w; j++ {
				route[i][j] = scanInt()
			}
		}
		route[h+1] = make([]int, w+2)

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

C++: #include <bits/stdc++.h>
using namespace std;

int w,h;
int f[51][51];
int d[3] = {0,-1,1};

void dfs(int x, int y) {
    int i,j,nx,ny;
    f[x][y] = 0;
    for(i=0; i<3; i++)
        for(j=0; j<3; j++) {
            if(i+j == 0)
                continue;
            nx=x+d[i], ny=y+d[j];
            if(nx<0 || nx>=h || ny<0 || ny>=w)
                continue;
            if(f[nx][ny] == 1)
                dfs(nx,ny);
        }
}

int main() {
    int i,j,r;
    while(1) {
        r=0;
        cin >> w >> h;
        if(w+h == 0)
            break;

        for(i=0; i<h; i++)
            for(j=0; j<w; j++)
                cin >> f[i][j];
        
        for(i=0; i<h; i++)
            for(j=0; j<w; j++)
                if(f[i][j] == 1) {
                    dfs(i, j);
                    r++;
                }
        cout << r << endl;
    }
}

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

int a[52][52];
int w, h;
int yy[8] = {-1, 0, 0, 1, -1, -1, 1, 1};
int xx[8] = {0, 1, -1, 0, -1, 1, -1, 1};
int solve(int y, int x){
	if(a[y][x] == 0)return 0;
	a[y][x] = 0;
	int ans = 0;
	for(int i = 0;i < 8;i++){
		ans += solve(y+yy[i], x+xx[i]);
	}
	return 1;
}

int main(){
	int y, x;
	while(cin >> w >> h, w){
		int ans = 0;
		fill((int*)a, (int*)(a+52), 0);
		for(int i = 1;i <= h;i++)
		for(int j = 1;j <= w;j++)cin >> a[i][j];
		for(int i = 1;i <= h;i++){
			for(int j = 1;j <= w;j++){
				if(a[i][j])ans += solve(i, j);
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #define	_USE_MATH_DEFINES
#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>
#include <cstdio>
#include <string>
#include <cmath>
#include <cfloat>
#include <map>
#include <queue>
#include <stack>
#include <list>
using namespace std;
int x,y;
int o[52][52];
queue<int> q;
void tansaku(int j,int i){
	if(j<1||j>x||i<1||i>y||o[i][j]==0||o[i][j]==2){
		return ;
	}
	if(o[i][j]==1){
		if(q.empty())
		q.push(1);
		o[i][j]=2;
	}
	
	tansaku(j+1,i);
	tansaku(j-1,i);
	tansaku(j,i+1);
	tansaku(j,i-1);
	tansaku(j+1,i+1);
	tansaku(j-1,i-1);
	tansaku(j+1,i-1);
	tansaku(j-1,i+1);
}
int main(){

	while(cin>>x>>y,x!=0||y!=0){
		int count=0;
		for(int i=1;i<=y;i++){
			for(int j=1;j<=x;j++){
				cin>>o[i][j];
			}
		}
		for(int i=1;i<=y;i++){
			for(int j=1;j<=x;j++){
				tansaku(j,i);
				if(!q.empty()){
				count+=q.front();
				}
				q.pop();
			}
		}
		
		cout<<count<<endl;
	}

}

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

int islands=0;
int w,h;
int field[50][50];
void bfs(int, int);

int main(){

  while(cin>>w>>h&&w!=0&&h!=0){

    for(int i=0;i<51;i++){
      for(int j=0;j<51;j++){
        field[i][j] = -1;
      }
    }

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        cin >> field[i][j];
        //        cout << field[i][j] << " ";
      }
      //    cout << endl;
    }
    // cout << endl;
    int ans=0; 

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        if(field[i][j]==1){
          field[i][j]=0;
          bfs(i,j);
          ans++;
        }
      }
    }
    /*   if(w==5&&h==4){
         for(int i=0;i<w;i++){
         for(int j=0;j<h;j++){
         cout << field[i][j] << " ";
         }
         cout << endl;
         }
         }*/
    cout << ans << endl;
  }

  return 0;
}

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

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

#define MAX 51

bool field[MAX][MAX];
int cnt;
int H, W;

void dfs(int x, int y){
  field[x][y] = 0;
  
  for(int dx = -1 ; dx <= 1 ; dx++){
    for(int dy = -1 ; dy <= 1 ; dy++){
      int nx = x + dx;
      int ny = y + dy;
      if(0 <= nx && nx < H && 0 <= ny && ny < W && field[nx][ny] == 1) dfs(nx, ny);
    }
  }
}

int main(){
  while(cin >> W >> H){
    cnt = 0;
    if(W == 0 && H == 0) break;
    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	cin >> field[i][j];
      }
    }

    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	if(field[i][j] == 1){
	  dfs(i, j);
	  cnt++;
	}
      }
    }
    cout << cnt << endl;
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

typedef pair<int, int> P;
int w,h;

void dfs(int x, int y, vector<vector<bool>> &maze){
    queue<P> q;
    q.push({x, y});
    maze[x][y] = false;
    while(q.size() > 0){
        int nx = q.front().first;
        int ny = q.front().second;
        q.pop();
        for (int i = -1; i <= 1; i++){
            for (int j = -1; j <= 1; j++){
                if (0 <= nx+i && nx+i < h && 0 <= ny+j && ny+j < w && maze[nx+i][ny+j]){
                    maze[nx+i][ny+j] = false;
                    q.push({nx+i, ny+j});
                }
            }
        }
    }
}

int main(){
    int x;
    int ans;
    while(1){
        cin >> w >> h;
        if (w == 0 || h == 0) break;
        vector<vector<bool>> maze(h, vector<bool>(w));
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                cin >> x;
                maze[i][j] = x;
            }
        }
        
        ans = 0;
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                if (maze[i][j]){
                    dfs(i, j, maze);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }
}

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

using namespace std;


#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

int h,w;

int c[52][52];

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


void dfs(int i,int j);



int main(){


	while(1){
		cin >> w >> ;

		if(h==0 && w == 0){
			break;
		}

		cnt=0;

		REP(i,h){
			REP(j,w){


				cin >> c[i][j] ;

			}
		}

		REP(i,h){
			REP(j,w){

				//cnt++??????????????\???????????????????????\???????????????
				if(c[i][j] == 1){
					cnt++;
					dfs(j,i);
				}
			}
		}

		cout << cnt << endl;
	}
	return 0;
}

void dfs(int i,int j){

	if(c[j][i] == 1){

		c[j][i] = 0;
		REP(k,8){
			//w???<=???????????£??????????????????
			if(0 <= i+dx[k] && i+dx[k] < w && 0 <= j+dy[k] && j+dy[k] < h){

				dfs(i+dx[k],j+dy[k]);
			}
		}
	}
}