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>
using namespace std;

int A[51][51];
int member[51][51];
int count = 0;

void check_member(int i,int j,int h, int w){
    if(member[i][j] == 0 && A[i][j] == 1 && i <= h && j <= w){
        member[i][j] = count;
        check_member(  i,  j+1 , h , w);
        check_member(i+1 , j+1 , h , w);
        check_member(i+1 ,   j , h , w);
        check_member(i+1 , j-1 , h , w);
        check_member(  i , j-1 , h , w);
        check_member(i-1 , j-1 , h , w);
        check_member(i-1 ,   j , h , w);
        check_member(i-1 , j+1 , h , w);
    }else{
        return;
    }
}


int main(){
    vector<int> result;
    int h,w;
    while(cin >> w >> h){
        if(h == 0 && w == 0) break;
        count = 0;
        for(int i = 0; i <= h; i++){
            for(int j = 0; j <= w; j++){
                if(i > 0 && j > 0){
                    cin >> A[i][j];
                }else{
                    A[i][j] = 0;
                }
                member[i][j] = 0;
            }
        }
        for(int i = 1; i <= h; i++){
            for(int j = 1; j <= w; j++){
                if(A[i][j]==1 && member[i][j] == 0){
                    count++;
                    check_member(i,j,h,w);
                }
            }
        }
        result.push_back(count);
    }
    for(int i = 0; i < result.size(); i++){
        cout << result[i] << endl;
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <cmath>
#include <set>
#include <algorithm>

typedef long long ll;
const ll MOD = 1e9 + 7;
const long long INF = 1LL<<60;
const double PI=3.14159265358979323846;
const int NMAX=100005;
using namespace std;

int done[51][51];
int c[51][51];

void dfs(int i, int j, int w, int h){
    if(i < 0 || i >= h || j < 0 || j >= w) return;
    if(done[i][j] != 0) return;

    done[i][j] = 1;
    
    if(c[i][j] == 1){
        dfs(i-1,j-1,w,h);
        dfs(i-1,j,w,h);
        dfs(i-1,j+1,w,h);
        dfs(i,j-1,w,h);
        dfs(i,j+1,w,h);
        dfs(i+1,j-1,w,h);
        dfs(i+1,j,w,h);
        dfs(i+1,j+1,w,h);
    }
}

void solve(int w, int h){
    for(int i = 0; i < h; i++){
        for(int j = 0; j < w; j++){
            cin >> c[i][j];
            done[i][j] = 0;
        }
    }
    int ans = 0;
    for(int i = 0; i < h; i++){
        for(int j = 0; j < w; j++){
            if(done[i][j] == 0 && c[i][j] == 1){
                ans += 1;
                dfs(i,j,w,h);
            }
        }
    }
    cout << ans << endl;
}

int main(){
    while(true){
        int w,h;
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        solve(w,h);
    }

    return 0;
}

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 <= w;i++){
            for(j = 1;j <= h;j++){
                cin >> c[i][j];
            }
        }
        a = 0;
        for(i = 1;i <= w;i++){
            for(j = 1;j <= h;j++){
                if(c[i][j]){
                    er(i,j);
                    a++;
                }
            }
        }
        cout << a << endl;
    }
}

C++: #include<iostream>
using namespace std;
int w,h;
int masu[1010][1010];
int dx[] = {-1,-1,-1,0,0,1,1,1};
int dy[] = {-1,0,1,-1,1,-1,0,1};
void dfs(int y,int x){
    masu[y][x] = 0;
    for(int i=0;i<8;i++){
        int ny = y+dy[i];
        int nx = x+dx[i];
        if(ny<0||ny>=h||nx<0||nx>=w||masu[ny][nx]==0) continue;
        dfs(ny,nx);
    }
}
int main(){
    int ans;
    while(cin >> w >> h,w!=0||h!=0){
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++) cin >> masu[i][j];
        }
        ans = 0;
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                if(masu[i][j] == 1){
                    ans++;
                    dfs(i,j);
                }
            }
        }
        cout << ans << endl;
    }
    return(0);
}

C++: #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int dx[8] = {1, 1, 0, -1, -1, -1, 0, 1}, dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};
ll seen[55][55];
ll W, H;
void dfs(int h, int w) {
    seen[h][w] = 0;
    
    for (ll dir = 0; dir < 8; dir++) {
        ll nh = h + dx[dir];
        ll nw = w + dy[dir];
        if (nh < 0 || nh >= H || nw < 0 || nw >= W) continue;
        if (seen[nh][nw] == 0) continue;
        
        
        dfs(nh, nw);
            
    }
}


int main(){
    while(1 > 0){
        ll ans = 0;
        cin >> W >> H;
        if(W == 0 && H == 0) break;

        for (ll i = 0; i < H; i++) {
            for (ll j = 0; j < W; j++) {
                cin >> seen[i][j];
            }
        }

        for (ll i = 0; i < H; i++) {
            for (ll j = 0; j < W; j++) {
                if(seen[i][j]){
                    dfs(i,j);
                    ans++ ;
                }
            }
        }
        printf("%lld\n", ans);
    }

    return 0;
}