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 <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
#define chmin(a, b) ((a)=min((a), (b)))
#define chmax(a, b) ((a)=max((a), (b)))
#define fs first
#define sc second
#define eb emplace_back
using namespace std;

typedef long long ll;
typedef pair<int, int> P;
typedef tuple<int, int, int> T;

const ll MOD=1e9+7;
const ll INF=1e18;
const double pi=acos(-1);
const double eps=1e-10;

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

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

        vector<vector<int>> c(h, vector<int>(w));
        for(int i=0; i<h; i++){
            for(int j=0; j<w; j++){
                cin>>c[i][j];
            }
        }

        int ans=0;
        for(int i=0; i<h; i++){
            for(int j=0; j<w; j++){
                if(c[i][j]){
                    ans++;
                    c[i][j] = 0;

                    queue<P> que;
                    que.push(P(i, j));
                    while(que.size()){
                        int cy, cx;
                        tie(cy, cx) = que.front();
                        que.pop();

                        for(int k=0; k<8; k++){
                            int ny = cy + dy[k];
                            int nx = cx + dx[k];

                            if(0 <= ny && ny < h && 0 <= nx && nx < w){
                                if(c[ny][nx]){
                                    c[ny][nx] = 0;
                                    que.push(P(ny, nx));
                                }
                            }
                        }
                    }
                }
            }
        }

        cout << ans << endl;
    }
}

C++: #include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#define mod 1000000007 //1e9+7
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 201

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

int mm[SIZE][SIZE];
int h,w;

bool dfs(int y,int x){
  
  if(y<0 || h<=y || x<0 || w<=x) return false;
  if(mm[y][x]==0) return false;
  mm[y][x] = 0;
  
  for(int i=0;i<8;i++){
    dfs(y+dy[i],x+dx[i]);
  }

  return true;
}

void calc(){
  int ans = 0;

  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      scanf("%d",mm[i]+j);
    }
  }

  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      ans += dfs(i,j);
    }
  }
  
  printf("%d\n",ans);
}

int main(){
  
  while(1){
    scanf("%d%d",&w,&h);
    if(h==0) break;
    calc();
  }
  
  return 0;
}

C++: #include <iostream>
#include <cstdio>
using namespace std;
#define N 50

const int dx[]={-1,-1,-1,0,0,1,1,1};
const int dy[]={-1,0,1,-1,1,-1,0,1};
int w,h;
int map[N][N];

void rec(int y,int x){
	map[y][x]=0;
	for(int i=0;i<8;i++){
		int nextx = x + dx[i];
		int nexty = y + dy[i];
		if(nextx>=0&&nexty>=0&&nextx<w&&nexty<h){
			if(map[nexty][nextx]==1){
				rec(nexty,nextx);
			}
		}
	}

}
	

int main(){

	while(cin >> w >> h){
		if(w==0&&h==0) break;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				scanf("%d",&map[i][j]);
			}
		}
	
		int count=0;
	
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(map[i][j]==1){
					rec(i,j);
					count++;
				}
			}
		}
		cout<<count<<endl;
	}

	return 0;
}

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

using namespace std;

bool base[50][50] = {};

void dfs( int const y, int const x, int const w, int const h )
{
  if ( x >= 0 && y >= 0 && x < w && y < h && base[y][x] ) {
      base[y][x] = false;
      dfs( y + 1, x, w, h );
      dfs( y - 1, x, w, h );
      dfs( y, x + 1, w, h );
      dfs( y, x - 1, w, h );
      dfs( y + 1, x + 1, w, h );
      dfs( y - 1, x - 1, w, h );
      dfs( y - 1, x + 1, w, h );
      dfs( y + 1, x - 1, w, h );
  }
}


int main()
{
  for(;;) {
    
    int w, h;
    cin >> w >> h;

    if ( w == 0 && h == 0 )
      break;

    for( int i=0; i<50; ++i )
      for( int j=0; j<50; ++j )
	base[i][j] = false;

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

    int count = 0;
    for( int i=0; i<h; ++i ) {
      for( int j=0; j<w; ++j ) {
	if ( base[i][j] ) {
	  dfs( i, j, w, h );
	  ++count;
	}
      }
    }
    
    cout << count << endl;
  }
}

C++: # include <iostream>

const int MAX_W = 50;
const int MAX_H = 50;

int w, h;

int c[MAX_H][MAX_W];

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

void dfs(int x, int y) {
	c[y][x] = 0;
	for (int i = 0; i < 8; ++i) {
		int nx = x + dx[i];
		int ny = y + dy[i];
		if (nx<0 || ny<0 || nx>w || ny>h)
			continue;
		if (c[ny][nx])
			dfs(nx, ny);
	}
}

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

int main() {
	while (1) {
		std::cin >> w >> h;
		if ((w + h) == 0)
			break;
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w; ++j)
				std::cin >> c[i][j];
		}
		std::cout << solve() << std::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;
}