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>
typedef long long ll;
#define ALL(l)  (l).begin(),(l).end()
#define rep(i,n) for(ll (i)=0;(i)<(n);(i)++)
#define rep2(i, s, n) for (ll i = (s); i < (ll)(n); i++)
using namespace std;

//const ll mod =  1000000007;
//const ll maxn = 1000000000;

//---------------------------------------------------------------------------------------------------
using vi = vector<int>; // intの1次元の型に vi という別名をつける
using vll = vector<ll>; // intの1次元の型に vi という別名をつける
using vvll = vector<vll>; // intの2次元の型に vvi という別名をつける
using vs = vector<string>; // stringの1次元の型に vs という別名をつける
using pll = pair<ll, ll>; // これ以降 pii という型名はpair<ll, ll> と同じ意味で使える
//---------------------------------------------------------------------------------------------------

int w,h;
vvll a(50,vll(50));

void dfs(int x,int y){
     a.at(x).at(y)=0;
     rep2(dx,-1,2){
       rep2(dy,-1,2){
         int  nx=x+dx;
         int  ny=y+dy;
           if(0<=nx&&nx<h&&0<=ny&&ny<w){
                if(a.at(nx).at(ny)==1){
                    dfs(nx,ny) ;         
                           }
                       }
                   }
               }                                  
}


int main() {
   while(1){
   cin>>w>>h;
   if(w==0&&h==0)break;
   else{
   rep(i,h){
       rep(j,w)cin>>a.at(i).at(j);
   }
  
   int ans=0;
   rep(i,h){
       rep(j,w){
           if(a.at(i).at(j)==1){
               
               
               dfs(i,j);
               ans++;
               
           }
       }
   }
   
  
   cout<<ans<<endl;
   }
   }
    
}

C++: #include<iostream>
#include<stack>
using namespace std;
int dx[8]={0,1,1,1,0,-1,-1,-1};
int dy[8]={-1,-1,0,1,1,1,0,-1};
int main()
{
	int n,m;
	while(cin>>n>>m,n) 
	{
		int f[m][n];
		for(int i = 0; i < m; ++i)
		{
			for(int j = 0; j < n; ++j)
			{
				cin>>f[i][j];
			}
		}

		int ans=0;
		for(int i = 0; i < m; ++i)
		{
			for(int j = 0; j < n; ++j)
			{
				if(f[i][j]==1)
				{
					ans++;
					stack<int> xs,ys;
					xs.push(j); ys.push(i);
					while(!xs.empty()) 
					{
						int x=xs.top(),y=ys.top();
						xs.pop(); ys.pop();
						f[y][x]=0;
						for(int k = 0; k < 8; ++k)
						{
							int nx=x+dx[k],ny=y+dy[k];
							if(0<=nx&&nx<n&&0<=y&&y<m&&f[ny][nx]==1)
							{
								xs.push(nx); ys.push(ny);
							}
						}
					}
				}
			}
		}
		cout<<ans<<endl;
	}
  return 0;
}

C++: #include <bits/stdc++.h>
#define INF 1e18
#define int long long
#define Rep(i, a, n) for (int i = (a); i < (n); i++)
#define Repr(i, n, a) for (int i = (n); i >= (a); i--)
#define rep(i, n) Rep(i, 0, n)
#define repr(i, n) Repr(i, n, 0)
#define all(a) a.begin(), a.end()
using namespace std;
typedef pair<int, int> P;
typedef pair<int, P> PP;
const int mod = 1000000007;

int w, h;
int c[60][60];

void solve(int x, int y)
{
    if (x < 0 || h <= x || y < 0 || w <= y)
        return;
    if (c[x][y] == 0)
        return;
    c[x][y] = 0;
    for (int i = -1; i < 2; i++)
    {
        for (int j = -1; j < 2; j++)
        {
            solve(x + i, y + j);
        }
    }
}

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

    while (1)
    {
        cin >> w >> h;
        if (h == 0)
            break;
        rep(i, h)
        {
            rep(j, w)
            {
                cin >> c[i][j];
            }
        }
        int ans = 0;
        rep(i, h)
        {
            rep(j, w)
            {
                if (c[i][j] == 1)
                {
                    solve(i, j);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }
}

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

int map[50][50];

typedef pair<int, int> pxy;

int h, w, ans = 0;

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

void bfs(int sx, int sy)
{
  queue<pxy> q;
  q.push(pxy(sx, sy)); 
  while(!q.empty()){
    int x, y;
    x = q.front().first;
    y = q.front().second;
    q.pop();
    if(map[x][y]){
      map[x][y] = 0;
      for(int i = 0; i < 8; i++){
	int next_x = x + dx[i], next_y = y + dy[i];
	if(map[next_x][next_y] && next_x < w && next_x >= 0 && next_y < h && next_y >= 0){
	  q.push(pxy(next_x, next_y));
	}
      }
    }
  }
}

int main()
{
  while(1){
    cin >> w >> h;
    if(w == 0 && h == 0){
      break;
    }else{
      for(int i = 0; i < h; i++)
	for(int j = 0; j < w; j++)
	  cin >> map[j][i];
      for(int i = 0; i < h; i++)
	for(int j = 0; j < w; j++)
	  if(map[j][i]){
	    ans++;
	    bfs(j, i);
	  }
      cout << ans << endl;
      ans = 0;
    }
  }
}

C++: #include <bits/stdc++.h>
using namespace std;

int state[100][100];
bool reached[100][100];
int w,h;

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

void dfs(int x, int y) {

	if(x==0 || w<x || y==0 || h<y || state[x][y] == 0)
		return;
	if(reached[x][y] == true)
		return;

	reached[x][y]=true;

	for(int i=0; i<8; i++) {
		dfs(x+dx[i],y+dy[i]);
	}
}

int main() {

	while(1){
		cin >> w >> h;
		if(w==0 && h==0) {
			return 0;
		}
		memset(state, 0, sizeof(state));
		memset(reached, false, sizeof(reached));
		for(int i=1; i<=h; i++) {
			for(int j=1; j<=w; j++) {
				cin >> state[i][j];
			}
		}
		int count=0;
		for(int i=1; i<=h; i++) {
			for(int j=1; j<=w; j++) {
				if(reached[i][j]==true || state[i][j] == 0)
					continue;
				else{
					dfs(i,j);
					count++;
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}

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

int dx[8]={-1,-1,-1,0,1,1,1,0};
int dy[8]={1,0,-1,-1,-1,0,1,1};
int m,n;
bool v[51][51];
int ma[51][51];

void go(int x,int y){
    v[y][x]=1;
    for(int i=0;i<8;i++){
        int nx=x+dx[i];
        int ny=y+dy[i];
        if(nx>=0&&nx<m&&ny>=0&&ny<n&&!v[ny][nx]&&ma[ny][nx]==1){
            go(nx,ny);
        }
    }
}

int main(){
    while(cin>>m>>n,m){
        int ans=0;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                v[i][j]=0;
                cin>>ma[i][j];
            }
        }
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(v[i][j]==0&&ma[i][j]==1){
                    ans++;
                    go(j,i);
                }
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}