Go: ///
// File:  1160.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:45:57 2018
//
package main

import (
	"fmt"
)

var w, h int
var graph [][]string

func dfs(visited [][]bool, x, y int) {
	visited[x][y] = true

	for i := -1; i <= 1; i++ {
		for j := -1; j <= 1; j++ {
			dx := x + i
			dy := y + j
			if 0 <= dx && dx < h && 0 <= dy && dy < w && graph[dx][dy] == "1" && !visited[dx][dy] {
				dfs(visited, dx, dy)
			}
		}
	}
}

func main() {
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			break
		}

		graph = make([][]string, h)
		for i := range graph {
			graph[i] = make([]string, w)
		}

		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				var s string
				fmt.Scan(&s)
				graph[i][j] = s
			}
		}

		visited := make([][]bool, h)
		for i := range visited {
			visited[i] = make([]bool, w)
		}

		count := 0
		for i := range graph {
			for j := range graph[i] {
				if graph[i][j] == "1" && !visited[i][j] {
					dfs(visited, i, j)
					count++
				}
			}
		}

		fmt.Println(count)
	}
}

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

#define H_MAX 50
#define W_MAX 50

int field[H_MAX][W_MAX];

int w, h;

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

void dfs(int y, int x) {
    field[y][x] = 0;
    for (int i = 0; i < 8; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (0 <= nx && nx < w && 0 <= ny && ny < h && field[ny][nx]) {
            dfs(ny, nx);
        }
    }
}

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

int main() {
    memset(field, 0, sizeof(field));
    while (cin >> w >> h) {
        if (w == 0 && h == 0) break;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cin >> field[i][j];
            }
        }
        cout << count() << endl;
    }
    return 0;
}

C++: #include <iostream>

using namespace std;

int m[51][51];
int w, h;
int isl;
const int dx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int dy[] = {-1, -1, 0, 1, 1, 1, 0, -1};

void dfs(int x, int y)
{
    m[x][y] = 0;
    for (int i = 0; i < 8; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        
        if (nx < 0 || ny < 0 || nx > w || ny > h)
            continue;
        else if (m[nx][ny] == 1)
            dfs(nx, ny);
    }
}

int main()
{
    while (cin >> w >> h, w || h) {
        isl = 0;

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

        for (int i = 0; i < h; i++) 
            for (int j = 0; j < w; j++)
                if (m[i][j] == 1) {
    // for (int y = 0; y < h; y++) {
    //     for (int x = 0; x < w; x++)
    //         cout << m[y][x];
    //     cout << endl;
    // }
    // cout << endl;

                    dfs(i, j);
                    isl++;
                }
            
        cout << isl << endl;
    }

    return 0;
}

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

int w, h;
int maze[55][55];

void dfs(int y, int x){
	maze[y][x] = 0;
	//search8deg
	for(int i=-1; i<=1; i++){
		for(int j=-1; j<=1; j++){
			int nx = x - j;
			int ny = y - i;
			if(0 <= nx and nx < w and 0 <= ny and ny < h and maze[ny][nx] == 1){
				dfs(ny, nx);
			}
		}
	}
}

int main(){
while(1){	
	
	
	cin >> w >> h;
	if(w == 0 and h == 0) break;
	
	for(int i=0; i < h; i++){
		for(int j=0; j < w; j++){
			cin >> maze[i][j]; 
		}
	}
	
	int ans = 0;
	for(int i=0; i < h; i++){
		for(int j=0; j < w; j++){
			if(maze[i][j] == 1){
				dfs(i, j);
				ans += 1;
			}
		}
	}
	
	cout << ans << endl;
	
	
}//END
	return 0;
}

C++: #include <cstdio>
#define f(n)for(int i=0;i<n;i++)
#define s(w)scanf("%d",&w)
int a,n,m,d[99][99];
int u[16]={-1,-1,-1,0,0,1,1,1,-1,0,1,-1,1,-1,0,1};
void k(int x,int y){
	if(d[x][y]){d[x][y]=0;f(8)k(x+u[i],y+u[i+8]);}
}
int main(){
	a=0;
	s(n);s(m);
	if(n==0)return 0;
	f(9801)d[0][i]=0;
	f(n*m)s(d[i/n+1][i%n+1]);
	f(n*m)if(d[i/n+1][i%n+1])a++,k(i/n+1,i%n+1);
	printf("%d\n",a);
	main();
}

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

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

int H,W;
vector<vector<int>> field;
int cnt;

bool seen[510][510];
void dfs(int h,int w){
  seen[h][w] = true;

  for(int dir=0;dir<8;dir++){
    int nh=h+dx[dir];
    int nw=w+dy[dir];

    if(nh<0 || nh>=H || nw<0 || nw>=W) continue;
    if(field[nh][nw] == 0) continue;

    if(seen[nh][nw]) continue;

    dfs(nh,nw);
  }
}

int main(){
  cin >> W >> H;
  while(H!=0 || W!=0){
    field.resize(H);
    for(int i=0;i<H;i++){
      field[i].resize(W);
    }
    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++){
        seen[i][j] = false;
      }
    }
    cnt = 0;
    for(int i=0;i<H;i++){
      for(int j=0;j<W;j++){
        if(seen[i][j]) continue;
        if(field[i][j] == 1){
          dfs(i,j);
          cnt++;
        }
      }
    }

    cout << cnt << endl;
    cin >> W >> H;
  }
}

C++: #include <iostream>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <algorithm>
using namespace std;

void solve(vector<vector<bool> > land)
{
	vector<vector<bool> > check(land.size(), vector<bool>(land[0].size(), false));

	int num = 0;
	for(unsigned i=1; i<land.size()-1; ++i){
		for(unsigned j=1; j<land[0].size()-1; ++j){
			if(!land[i][j] || check[i][j])
				continue;
			check[i][j] = true;
			++ num;

			queue<pair<int, int> > place;
			place.push(make_pair(i,j));
			while(!place.empty()){
				int y = place.front().first;
				int x = place.front().second;
				for(int dy=-1; dy<=1; ++dy){
					for(int dx=-1; dx<=1; ++dx){
						if(land[y+dy][x+dx] && !check[y+dy][x+dx]){
							check[y+dy][x+dx] = true;
							place.push(make_pair(y+dy, x+dx));
						}
					}
				}
				place.pop();
			}
		}
	}

	cout << num << endl;
}

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

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

		solve(land);
	}

	return 0;
}

C++: #include <iostream>
#include <cstdio>
using namespace std;
char field[51][51];
int W, H;

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

int main(void) {
  while(cin >> W >> H, W != 0 && H != 0) {
    int res = 0;
    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);
	  res++;
	  /*cout << endl;
	  for(int b = 0 ; b < H ; b++) {
	    for(int a = 0 ; a < W ; a++) {
	      cout << field[b][a] << ' ';
	    }
	    cout << endl;
	  }
	  cout << endl;*/
	}
      }
    }
    cout << res << endl;
  }
  return 0;
}