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<cstdio>
using namespace std;
void func(int,int);
int a,b;
int sima[51][51];
int cnt;
int main(void)
{
	int i,j,x,y;
	scanf("%d",&a);
	scanf("%d",&b);
	while(!(b==0 && a==0)){
		
		for(i=0;i<b;i++){
			for(j=0;j<a;j++){
				scanf("%d",&sima[i][j]);
			}
		}
		cnt=0;
		for(i=0;i<b;i++){
			for(j=0;j<a;j++){
				if(sima[i][j]==1){
					func(i,j);
					cnt++;
				}
			}
		}
		printf("%d\n",cnt);
		scanf("%d",&a);
		scanf("%d",&b);
	}
	return 0;
}
void func(int y,int x)
{
	if(y-1>=0){
		if(sima[y-1][x]==1){
			sima[y-1][x]=0;
			func(y-1,x);
		}
	}
	if(x-1>=0){
		if(sima[y][x-1]==1){
			sima[y][x-1]=0;
			func(y,x-1);	
		}
	}
	if(y+1<=a){
		if(sima[y+1][x]==1){
			sima[y+1][x]=0;
			func(y+1,x);
		}
	}
	if(x+1<=b){
		if(sima[y][x+1]==1){
			sima[y][x+1]=0;
			func(y,x+1);
		}
	}
	if(y-1>=0 && x+1<=b){
		if(sima[y-1][x+1]==1){
			sima[y-1][x+1]=0;
			func(y-1,x+1);
		}
	}
	if(y-1>=0 && x-1>=0){
		if(sima[y-1][x-1]==1){
			sima[y-1][x-1]=0;
			func(y-1,x-1);
		}
	}
	if(y+1<=a && x+1<=b){
		if(sima[y+1][x+1]==1){
			sima[y+1][x+1]=0;
			func(y+1,x+1);
		}
	}
	if(y+1<=a && x-1>=0){
		if(sima[y+1][x-1]==1){
			sima[y+1][x-1]=0;
			func(y+1,x-1);
		}
	}
}

C++: #include <iostream>
#include <vector>
using namespace std;
#define repeat(i,n) for (int i = 0; (i) <(int) (n); ++(i))
#define repeat_from(i,m,n) for (int i = (m); (i) <(int) (n); ++(i))
void dfs(int x, int y, int n, vector<vector<int> > & k, vector<vector<bool> > const & c) {
    int h = c.size();
    int w = c.front().size();
    if (x < 0 or w <= x or y < 0 or h <= y) return;
    if (k[y][x] or not c[y][x]) return;
    k[y][x] = n;
    repeat_from (dy,-1,1+1) {
        repeat_from (dx,-1,1+1) {
            dfs(x+dx,y+dy,n,k,c);
        }
    }
}
int solve(vector<vector<bool> > const & c) {
    int h = c.size();
    int w = c.front().size();
    vector<vector<int> > k(h, vector<int>(w, 0));
    int n = 0;
    repeat (y,h) {
        repeat (x,w) {
            if (not k[y][x] and c[y][x]) {
                dfs(x,y,++n,k,c);
            }
        }
    }
    return n;
}
int main(void) {
    while (true) {
        int w, h; cin >> w >> h;
        if (w == 0 and h == 0) break;
        vector<vector<bool> > c(h, vector<bool>(w));
        repeat (y,h) {
            repeat (x,w) {
                int t; cin >> t;
                c[y][x] = t;
            }
        }
        cout << solve(c) << endl;
    }
    return 0;
}

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

int ans = 0;
int w,h;
int map[100][100] ={};


void search(int y,int x){

  //  cout << "search"<< y <<" " << x << endl;
  map[y][x] = 0;

  for(int dy = -1 ; dy <= 1 ; dy++){
    for(int dx = -1 ; dx <= 1 ; dx++){
      int nx = x + dx, ny = y + dy;
      if(nx >= 0 && ny >= 0 && nx < w && ny < h && map[ny][nx] == 1 ){
	search(ny,nx);
      }
    }
  }
  /*
    if( map[y][x] == 0 ){
    //テ・ツ渉ウテァツォツッ
    if(x+1 == w){
      //テヲツ慊?・ツセツ?
      if(y+1 == h){
      }
      //テヲツ慊?」ツつづ、ツクツ凝」ツ?ョテヲツョツオ
      else{
	search(y+1,x);
    }else{
      search(y,x+1);
    }
  }
  */
}


int main(){

  while(1){

    ans = 0;
    cin >> w >> h ;

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

    for(int i = 0 ; i < h ; i++){
      for(int j = 0 ; j < w ; j++){
	cin >> map[i][j];
      }
    }
    //map テ・ツ?コテ・ツ環?
    /*
    for(int i = 0 ; i < h ; i++){
      for(int j = 0 ; j < w ; j++){
	cout << map[i][j];
      }
      cout << endl;
    }
    //    cout << endl;
    */
    for(int i = 0 ; i < h ; i++){
      for(int j = 0 ; j < w ; j++){
	if(map[i][j] == 1){
	  ans++;
	  search(i,j);
	}
      }
    }
    cout << ans << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cstring>

#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)

using namespace std;

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

bool memo[55][55];
int d[55][55];

bool can(int y,int x) {
    if(0 <= y && y < h && 0 <= x && x < w) return true;
    return false;
}

void dfs(int y,int x) {
    if(memo[y][x]) return;
    memo[y][x] = true;
    
    rep(i,8) {
        int ny = y + dy[i];
        int nx = x + dx[i];
        
        if(can(ny,nx) && d[ny][nx] == 1) {
            dfs(ny,nx);
        }
    }
}


int main()
{
    while(cin >> w >> h)
    {
        if(w == 0 && h == 0) break;
        
        memset(d,0,sizeof(d));
        memset(memo,0,sizeof(memo));

        rep(i,h) {
            rep(j,w) {
                cin >> d[i][j];
            }
        }
        
        int ans = 0;
        rep(i,h) {
            rep(j,w) {
                if(!memo[i][j] && d[i][j] == 1) {
                    ans++;
                    dfs(i,j);
                }
            }
        }

        cout << ans << endl;
    }

    return 0;
}