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<bits/stdc++.h>
using namespace std;
#define inf 1e9
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=m;i<n;i++)
#define RFOR(i,m,n) for(int i=m;i>=n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265


void f(int w,int h){
  int map[100][100]={};
  bool c[100][100]={};

  rep(i,h){
    rep(j,w){
      cin>>map[i][j];
    }
  }

  int ans=0;
  rep(i,h){
    rep(j,w){
      if(map[i][j]&&!c[i][j]){
        
        queue<P> q;
        q.push(P(i,j));
        while(q.size()){
          P p=q.front(); q.pop();
          int a=p.first,b=p.second;
          for(int k=-1;k<2;k++){
            for(int l=-1;l<2;l++){
              int y=a+k;
              int x=b+l;
              if(0<=x&&x<w&&0<=y&&y<h)
              if(map[y][x]&&!c[y][x]){
                c[y][x]=true;
                q.push(P(y,x));
              }
            }
          }
        }
        ans++;
      }
    }
  }

  cout<<ans<<endl;
}

int main(){
  int w,h;
  while(1){
    cin>>w>>h;
    if(w==0) break;
    f(w,h);
  }

  return 0;
}

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

//int Flag=0;

void find_island(int *cp){
//	int length=cp-c1;

	*cp=0;
	
	if(*(cp+1)==1) find_island(cp+1);
	if(*(cp+52)==1)find_island(cp+52);
	if(*(cp+53)==1)find_island(cp+53);
	if(*(cp-1)==1)find_island(cp-1);
	if(*(cp-51)==1)find_island(cp-51);
	if(*(cp-52)==1)find_island(cp-52);
	if(*(cp-53)==1)find_island(cp-53);
	if(*(cp+51)==1)find_island(cp+51);	
}


int main()
{
	int w,h;

	cin>>w>>h;
	while( w!=0 || h!=0 ){
		int c[52][52]={},island=0;
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				cin>>c[i][j];
			}
		}

		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				if(c[i][j]==1){
					island++;
					find_island(&c[i][j]);
				}
			}
		}
		cout<<island<<endl;
		cin>>w>>h;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll=long long;
typedef pair<int,int> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
int w,h;
int nx,ny;
vector<vector<int>>G;
void dfs(int a,int b){
     if(0>nx|| nx>=h || 0>ny|| ny>=w) return ;
     if( G.at(nx).at(ny)==0) return ; 
     G.at(a).at(b)=0;
    for(int k=-1;k<=1;k++){
        for(int s=-1;s<=1;s++){
            nx=a+k;
            ny=b+s;
            dfs(nx,ny);
        }
    }
}
 
 
 
int main(){
    cin>>w>>h;
    G.resize(h,vector<int>(w));
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>G.at(i).at(j);
        }
    }
    int count=0;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(G.at(i).at(j)==1){
                count++;
                dfs(i,j);
            }
        }
    }
cout<<count<<endl;
}

C++: #include <iostream>

#define REP(i,n) for(int i=0; i<n; i++)
#define debug(x) cerr << #x << " = " << (x) << endl;

using namespace std;

int w, h, map[51][51], diff[9]={-1, 0, 1, 0, -1, 1, 1, -1, -1};

bool check(int j, int k){
	return (j>=0 && j<h && k>=0 && k<w && map[j][k]>0);
}

void dfs(int j, int k){
	REP(i,8){
		if (check(j+diff[i], k+diff[i+1])){
			map[j+diff[i]][k+diff[i+1]] = 0;
			dfs(j+diff[i],k+diff[i+1]);
		}
	}
	return;
}

int main(){
	while(1){
		int ans=0;
		cin >> w >> h;
		if (w==0 && h==0) break;
		REP(j,h){
			REP(k,w) map[j][k] = 0;
		}
		REP(j,h){
			REP(k,w) cin >> map[j][k];
		}
		REP(j,h){
			REP(k,w){
				if (check(j,k)){
					ans++;
					dfs(j,k);
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define pb(a) push_back(a)
#define pr(a) cout<<(a)<<endl
#define PR(a,b) cout<<(a)<<" "<<(b)<<endl
#define F first
#define S second
#define ll long long
bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,-1,0,1};
typedef pair<int,int> P;

int n,m;
int a[51][51];
bool d[51][51];

void dfs(int nx, int ny) {
  d[nx][ny]=true;
  REP(i,-1,2) {
    REP(j,-1,2) {
      int x=nx+i,y=ny+j;
      if(check(n,m,x,y) && a[x][y] && !d[x][y]) dfs(x,y);
    }
  }
}

int main() {
  while(cin >> m >> n && (n||m)) {
    rep(i,n) {
      rep(j,m) cin >> a[i][j];
    }
    memset(d,false,sizeof(d));
    int cnt=0;
    rep(i,n) {
      rep(j,m) {
	if(!d[i][j] && a[i][j]) {
	  cnt++;
	  dfs(i,j);
	}
      }
    }
    pr(cnt);
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define OUT(x) cout<<x<<endl
#define DEBUG(x) cout<<#x<<": "<<x
const int BA = 1000;
const int INFTY = (1<<21);
int c[51][51];
int w,h;
int del(int x,int y){
  if(x<0)return 0;
  if(c[x][y]){
    c[x][y] = 0;
    return del(x+1,y)+del(x,y+1)+del(x+1,y+1)+del(x-1,y+1);
    
  }
  else return 0;
  
}
int solve(int x,int y){
  if(x==0 && y == h)return 0;
  else if(x==w){
    return solve(0,y+1);
  }
  else if(c[x][y]==1){
    del(x,y);
    return solve(x+1,y)+1;
  }
  else return solve(x+1,y);
}
int main(){
  while(cin>>w>>h&&w&&h){
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin >> c[i][j];
      }
    }
    cout << solve(0,0) << endl;
  }
}

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

int w, h;
bool data[99][99]; //y,x

int solve(int x, int y){

  if(x < 0 || y < 0 || x == w || y == h) return 0;
  if(!data[y][x]) return 0;

  data[y][x] = false;

  for(int i=-1;i<2;i++) for(int j=-1;j<2;j++) solve(x+j, y+i);

  return 1;
}

int main(){

  while(true){
    cin >> w >> h;
    if(!w && !h) break;

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

    int ret = 0;
    for(int i=0;i<h;i++) for(int j=0;j<w;j++) if(data[i][j]) ret += solve(j, i);

    cout << ret << endl;
  }

}