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 <vector>
#include <string>
#include <cmath>
#include <algorithm>

using namespace std;

int c[52][52];

void er(int i,int j){
    c[i][j]--;
    if(c[i+1][j-1])
        er(i+1,j-1);
    if(c[i][j+1])
        er(i,j+1);
    if(c[i+1][j])
        er(i+1,j);
    if(c[i+1][j+1])
        er(i+1,j+1);
    if(c[i-1][j+1])
        er(i-1,j+1);
    if(c[i-1][j])
        er(i-1,j);
    if(c[i-1][j-1])
        er(i-1,j-1);
    if(c[i][j-1])
        er(i,j-1);
}

int main(void){
    int w,h;
    int i,j;
    int a;
    while(true){
        cin >> w >> h;
        if(w == 0){
            break;
        }
        for(i = 0;i < 52;i++){
            for(j = 0;j < 52;j++){
                c[i][j] = 0;
            }
        }
        for(i = 1;i <= h;i++){
            for(j = 1;j <= w;j++){
                cin >> c[i][j];
            }
        }
        a = 0;
        for(i = 1;i <= h;i++){
            for(j = 1;j <= w;j++){
                if(c[i][j]){
                    er(i,j);
                    a++;
                }
            }
        }
        cout << a << endl;
    }
}

C++: #include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <string>
#include <cstring>
#include <cmath>
#include <complex>
#include <map>
#include <climits>
using namespace std;

#define reep(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) reep((i),0,(n))
#define ALL(v) (v).begin(),(v).end()
#define PB push_back
#define EPS 1e-8
#define F first
#define S second
#define mkp make_pair

static const double PI=6*asin(0.5);
typedef long long ll;
typedef complex<double> CP;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vint;
static const int INF=1<<24;


int main(){
	int n,m;
	while(cin>>m>>n,n||m){
		int a[n][m];
		rep(i,n){
			rep(j,m){
				cin>>a[i][j];
				//cout<<a[i][j]<<" ";
			}
			//cout<<endl;
			
		}
		//cout<<endl;
		int ans=0;
		rep(i,n){
			rep(j,m){
				if(a[i][j]==1){
					a[i][j]=0;
					ans++;
					queue<pii> q;
					q.push(mkp(i,j));
					while(!q.empty()){
						int qs= q.size();
						rep(k,qs){
							pii tp=q.front();
							q.pop();
							int v[8][2]={0,1,0,-1,1,0,-1,0,1,1,1,-1,-1,1,-1,-1};
							rep(l,8){
								int x=tp.F+v[l][0],y=tp.S+v[l][1];
								if(x>=0&&y>=0&&x<n&&y<m){
									if(a[x][y]==1){
										q.push(mkp(x,y));
										a[x][y]=0;
									}
								}
							}
						}
					}/*
					
					rep(k,n){
						rep(l,m){
							cout<<a[k][l]<<" ";
						}
						cout<<endl;
					}
					cout<<endl;
					*/
				}
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define debug(x) cerr << #x << ": " << x << '\n';
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = (int)1e9;

int w, h;
int c[51][51];
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){
	c[y][x] = 0;
	for(int i = 0; i < 8; i++){
		int ny = y + dy[i], nx = x + dx[i];
		if(0<=ny and ny<h and 0<=nx and nx<w and c[ny][nx]==1){
			dfs(ny, nx);
		}
	}
}

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

	return res;
}

int main(void){
	while(scanf("%d%d", &w, &h) != EOF){
		if(w == 0 and h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &(c[i][j]));
			}
		}
		printf("%d\n", solve());
	}

	return 0;
}

C++: #include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
using ll = long long;
using vec = vector<ll>;
using vect = vector<double>;
using Graph = vector<vector<ll>>;
#define loop(i, n) for (ll i = 0; i < n; i++)
#define Loop(i, m, n) for (ll i = m; i < n; i++)
#define pool(i, n) for (ll i = n; i >= 0; i--)
#define Pool(i, m, n) for (ll i = n; i >= m; i--)
#define mod 1000000007ll;
#define setbit bitset<8>
#define flagcount __builtin_popcount
#define flag(x) (1 << x)
#define flagadd(bit, x) bit |= flag(x)
#define flagpop(bit, x) bit &= ~flag(x)
#define flagon(bit, i) bit &flag(i)
#define flagoff(bit, i) !(bit & (1 << i))
#define all(v) v.begin(), v.end()
#define low2way(v, x) lower_bound(all(v), x)
#define high2way(v, x) upper_bound(all(v), x)
#define count2way(v, x) high2way(v, x) - low2way(v, x)
#define lower(v, x) low2way(v, x) - v.begin()       //1番左が0、もし見つから無いならｎを出力
#define higher(v, x) high2way(v, x) - v.begin() - 1 //1番左が0、もし見つからないならn-1を出力（注意）
#define putout(a) cout << a << endl
#define putout2(a, b) \
  putout(a);          \
  putout(b)
#define putout3(a, b, c) \
  putout(a);             \
  putout(b);             \
  putout(c)
#define putout4(a, b, c, d) \
  putout(a);                \
  putout(b);                \
  putout(c);                \
  putout(d)
#define putout5(a, b, c, d, e) \
  putout(a);                   \
  putout(b);                   \
  putout(c);                   \
  putout(d);                   \
  putout(e)
#define Gput(a, b) G[a].push_back(b)
#define cin1(a) cin >> a
#define cin2(a, b) cin >> a >> b
#define cin3(a, b, c) cin >> a >> b >> c
#define cin4(a, b, c, d) cin >> a >> b >> c >> d
#define cin5(a, b, c, d, e) cin >> a >> b >> c >> d >> e
#define sum(v) accumulate(all(v), 0ll)
#define gcd(x, y) __gcd(x, y)
ll ctoi(char c)
{
  if (c >= '0' && c <= '9')
  {
    return c - '0';
  }
  return 0;
}
ll lcm(ll x, ll y)
{
  ll z = gcd(x, y);
  return x * y / z;
}
ll primejudge(ll n)
{
  if (n < 2)
    return 0;
  else if (n == 2)
    return 1;
  else if (n % 2 == 0)
    return 0;
  double sqrtn = sqrt(n);
  Loop(i, 3, sqrtn + 1)
  {
    if (n % i == 0)
    {
      return 0;
    }
    i++;
  }
  return 1;
}
//場合によって使い分ける
//const ll dx[4]={1,0,-1,0};
//const ll dy[4]={0,1,0,-1};
const ll dx[8]={1,1,0,-1,-1,-1,0,1};
const ll dy[8]={0,1,1,1,0,-1,-1,-1};

/*
//TIMESTAMPbfs
vector<bool> seen;
vec first;
vec last;
void dfs(const Graph &G,ll v,ll &time){
  if(!(seen[v])){
  seen[v]=true;
  first[v]=time++;
  for(auto next_v:G[v]){
    if(seen[next_v])continue;
    dfs(G,next_v,time);
  }
  last[v]=time++;
  }
}
//main関数内で
  seen.assign(n, false); // 全頂点を「未訪問」に初期化
  first.resize(n);
  last.resize(n);
*/
//多次元配列の宣言名
//vector<vector<ll>> field(h, vector<ll>(w));
//記念
/*
field.assign(h, vector<ll>(w, 0));
vector<vector<ll>> field;
void dfs(ll x,ll y,ll h,ll w){
  field[x][y]=0;
  loop(i,8){
    ll next_x=x+dx[i],next_y=y+dy[i];
    if(next_x<0||next_x>=h||next_y<0||next_y>=w)continue;
    if(field[next_x][next_y]==0)continue;
    dfs(next_x,next_y,h,w);
  }
}
*/
int main(){
  vec a={198,55,152,18,23,7,8,13,11,1,1,0,0,1};
  loop(i,14)putout(a[i]);
  return 0;
}