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>
#define rep(i,n) for(int i=0; i<(n); i++)
#define FOR(i,a,n) for(int i=(a); i<(n); i++)
#define all(v) v.begin(), v.end()
#define fi first
#define se second
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1e9;
const int MOD = 1e9+7;

int H, W;
int mat[50][50];
const int dh[] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dw[] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(int h, int w) {
	mat[h][w] = 0;
	rep(i, 8) {
		int nh = h+dh[i], nw = w+dw[i];
		if (nh>=0 && nh<H && nw>=0 && nw<W && mat[nh][nw]==1) dfs(nh, nw);
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	while (true) {
		cin >> W >> H;
		if (W+H == 0) break;
		
		memset(mat, 0, sizeof(mat));

		rep(i, H) {
			rep(j, W) cin >> mat[i][j];
		}

		int cnt = 0;
		rep(i, H) rep(j, W) {
			if (mat[i][j]==1) {
				dfs(i, j);
				cnt++;
			}
		}

		cout << cnt << endl;
	}
}

C++: #include<bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n ; i++)
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define whole(f, x, ...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x) // decltypeで型取得、引数があればva_argsのところに入れる
using namespace std;
typedef long long ll; // long longをllでかけるようにした
const int INF = 1e9;
int n, m;
char W[100][100];

void dfs(int y, int x){
    W[y][x] = '0';
    for(int dx = -1; dx <= 1; dx++){
        for(int dy = -1; dy <= 1; dy++){
            int nx = dx + x;
            int ny = dy + y;
            if(W[ny][nx] == '1' and 0 <= nx and nx < n and 0 <= ny and ny < m) dfs(ny, nx);
        }
    }
    return ;
}

int main(void){
    while(true){
        cin >> n >> m;
        if(n == 0 and m == 0) return 0;
        REP(i, m){
            REP(j, n){
                cin >> W[i][j];
            }
        }

        int ans = 0;
        REP(i, m){
            REP(j, n){
                if(W[i][j] == '1'){
                    dfs(i, j);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }
}

C++: #include<iostream>
using namespace std;
int g = 0;
int w, h;
int a[50][50];
int ans = 0;
void track(int i, int j) {
	for (int l = -1; l <= 1; l++) {
		for (int m = -1; m <= 1; m++) {
			/*int li = l + i;
			int mj = m + j;*/
			if (l+i < h && m+j < w && l+i >= 0 && m+j >= 0 && a[l+i][m+j] == 1) {
				g = 1;
				a[l+i][m+j] = 0;
				/*for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						cout << a[i][j];
						if (j == 4) { cout << endl; }
					}*/
					track(l+i, m+j);
				}
			}
		}
		/*for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cout << a[i][j];
				if (j == 4)cout << endl;
			}
		}*/
	}
int main() {
	while (1) {
		cin >> w >> h;
		if (w == 0 && h == 0) { return 0; }
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> a[i][j];
			}
		}
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				track(i, j);
				if (g == 1) { ans++; }
				g = 0;
			}
		}
		cout << ans << endl;
		ans = 0;
	}
}

C++: #include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,x,n) for(int i=(x);i<(n);i++)
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define mp make_pair
#define fir first
#define sec second
#define ub upper_bound
#define lb lower_bound
#define int long long
using namespace std;
const int MOD=1000000007;
const int INF=1000000009;

int dx[8]={1,0,-1,0,1,-1,-1,1};
int dy[8]={0,1,0,-1,1,1,-1,-1};
int h,w;
int MAP[100][100];

int bfs(int y,int x){
  rep(i,8){
    int ny=y+dy[i];
    int nx=x+dx[i];
    if(nx>=0&&ny>=0&&nx<w&&ny<h&&MAP[ny][nx]==1){
      MAP[ny][nx]=0;
      bfs(ny,nx);
    }
  }
  return 1;
}

signed main(){
  while(cin>>w>>h,w){
    rep(i,h)rep(j,w)cin>>MAP[i][j];
    int ans=0;
    rep(i,h)rep(j,w){
      if(MAP[i][j]==1)ans+=bfs(i,j);
    }
    cout<<ans<<endl;
  }
  return 0;
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
int field[52][52]={};
void umeru(int y,int x){
	field[y][x]=0;
	for(int i=-1;i<=1;i++){
		for(int j=-1;j<=1;j++){
			if(field[y+i][x+j])	umeru(y+i,x+j);
		}
	}
}
int main(){
	while(1){
		int w,h,cnt=0;
		cin >> w >> h;
		if(!w&&!h)	break;
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				cin >> field[i][j];
			}
		}
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				if(field[i][j]){
					cnt++;
					umeru(i,j);
				}
			}
		}
		cout << cnt << endl;
	}
}

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

using namespace std;

#define vec vector
#define rep(i, n) for (int i = 0; i < (int)n; i++)

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

int dp[55][55];
int c[55][55];

int check(int x, int y)
{
	if (dp[x][y]) return 0;
	if (c[x][y] == 0) return 0;
	dp[x][y] = 1;
	
	rep(i, 8) {
		int xx = x + dx[i];
		int yy = y + dy[i];
		int take = check(xx, yy);
	}
	return 1;
}

int main(void)
{
	while(1) {
		int w, h;
		cin >> w >> h;
		if (w == 0) break;
		rep(i, 55) rep(j, 55) c[i + 1][j + 1] = 0;
		rep(i, h) rep (j, w) cin >> c[i + 1][j + 1];
		rep(i, 55) rep(j, 55) dp[i][j] = 0;
		rep(i, 55) {
			dp[0][i] = 1;
			dp[i][0] = 1;
			dp[h + 1][i] = 1;
			dp[i][w + 1] = 1;
		}

		int ans = 0;
		rep(i, h) rep(j, w) if (c[i + 1][j + 1]) ans += check(i + 1, j + 1);
		cout << ans << endl;
	}
	return 0;
}

C++: #include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <queue>
#include <stack>
#include <string>
#include <vector>
#define INF 10000000
#define PI 3.14159265358979323846
using namespace std;
typedef long long ll;
typedef pair<int, int> p;
typedef vector<int> v;
typedef vector<int, int> v2;
typedef vector< pair<int, int> > vp;
int dx[4] = { 0, 1, 0, -1 };
int dy[4] = { 1, 0, -1, 0 };

int w, h;
int c[50][50];
int f[50][50];

bool dfs(int y, int x){
	if (c[y][x] == 0) return false;
	if (f[y][x] == 1) return false;
	
	f[y][x] = 1;
	if (y > 0) dfs(y - 1, x);
	if (x > 0) dfs(y, x - 1);
	
	if (y < h) dfs(y + 1, x);
	if (x < w) dfs(y, x + 1);

	if (y > 0 && x > 0) dfs(y - 1, x - 1);
	if (y < h && x > 0) dfs(y + 1, x - 1);
	if (y > 0 && x < w) dfs(y - 1, x + 1);
	if (y < h && x < w) dfs(y + 1, x + 1);

	return true;
}

int main(){
	ios::sync_with_stdio(false);

	while (1){
		cin >> w >>  h;
		if (w == 0 && h == 0) break;

		int ans = 0;

		for (int i = 0; i < h; i++)
			for (int j = 0; j < w; j++)
				cin >> c[i][j];
			
		for (int i = 0; i < h; i++)
			for (int j = 0; j < w; j++)
				f[i][j] = -1;
		
		for (int i = 0; i < h; i++)
			for (int j = 0; j < w; j++)
				if(dfs(i, j)) ans++;

		cout << ans << endl;

	}

	return 0;
}