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>
using namespace std;

int field[52][52];
int vw[8] = {-1,0,1,-1,1,-1,0,1};
int vh[8] = {-1,-1,-1,0,0,1,1,1};
void search(int i,int j)
{
	field[i][j] = 0;
	for(int k=0;k<8;k++){
		if(field[i+vw[k]][j+vh[k]] == 1)
			search(i+vw[k],j+vh[k]);
	}
}

int main()
{
	int w,h;
	while(cin >> w >> h){
		if(w == 0 && h == 0)
			break;
		for(int i=0;i<52;i++){
			for(int j=0;j<52;j++){
				field[i][j] = 0;
			}
		}
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				cin >> field[i][j];
			}
		}

		int count = 0;
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				if(field[i][j] == 1){
					count++;
					search(i,j);
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}

C++: #include<cstdio>
using namespace std;
void func(int,int);
int a,b;
int sima[51][51];
int cnt;
int main(void)
{
	int i,j;
	scanf("%d",&a);
	scanf("%d",&b);
	for(i=0;i<a;i++){
		for(j=0;j<b;j++){
			scanf("%d",&sima[i][j]);
		}
	}
	for(i=0;i<a;i++){
		for(j=0;j<b;j++){
			if(sima[i][j]==1){
				func(i,j);
				cnt++;
			}
		}
	}
	printf("%d\n",cnt);
	return 0;
}
void func(int y,int x)
{
	if(y-1>=0){
		if(sima[y-1][x]==1){
			func(y-1,x);
		}
	}
	if(x-1>=0){
		if(sima[y][x-1]==1){
			func(y,x-1);
		}
	}
	if(y+1<=a){
		if(sima[y+1][x]==1){
			func(y+1,x);
		}
	}
	if(x+1<=b){
		if(sima[y][x+1]==1){
			func(y,x+1);
		}
	}
	if(y-1>=0 && x+1<=b){
		if(sima[y-1][x+1]==1){
			func(y-1,x+1);
		}
	}
	if(y-1>=0 && x-1>=0){
		if(sima[y-1][x-1]==1){
			func(y-1,x-1);
		}
	}
	if(y+1<=a && x+1<=b){
		if(sima[y+1][x+1]){
			func(y+1,x+1);
		}
	}
	if(y+1<=a && x-1>=0){
		if(sima[y+1][x-1]){
			func(y+1,x-1);
		}
	}
}

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

int w, h;
vector< vector<int> > c;

void Dfs(int i, int j) {
  c[i][j] = 0;
  for (int di = -1; di <= 1; ++di) {
    for (int dj = -1; dj <= 1; ++dj) {
      if (di == 0 && dj == 0)
        continue;

      int ni = i + di, nj = j + dj;
      if (ni < 0 || ni >= h || nj < 0 || nj >= w) continue;
      if (c[ni][nj]) Dfs(ni, nj);
    }
  }
}

int main() {
  while (true) {
    cin >> w >> h;

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

    c.resize(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]) {
          Dfs(i, j);
          ++ans;
        }
      }
    }
    c.clear();

    cout << ans << endl;
  }
}

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

using namespace std;

typedef long long ll;
typedef vector<int> VI;

#define FOR(i,n) for(int (i)=0;(i)<(n);(i)++)
#define FOR1(i,n) for(int (i)=1;(i)<(n);(i)++)
#define eFOR(i,n) for(int (i)=0;(i)<=(n);(i)++)
#define eFOR1(i,n) for(int (i)=1;(i)<=(n);(i)++)
#define SORT(i) sort((i).begin(),(i).end())
constexpr auto INF = 1000000000;
constexpr auto LLINF = 9223372036854775807;
constexpr auto mod = 1000000007;

int w, h, c[50][50];
int dx[8] = { -1,0,1,-1,1,-1,0,1 }, dy[8] = { -1,-1,-1,0,0,1,1,1 };
void search(int x, int y) {
	if (x >= 0 && x < w && y >= 0 && y < h) {
		if (c[y][x] == 1) {
			c[y][x] = 0;
			FOR(k, 8)search(x + dx[k], y + dy[k]);
		}
	}
}

int main() {
	while (1) {
		cin >> w >> h;
		if (w == 0 && h == 0)break;
		FOR(i, h)FOR(j, w)cin >> c[i][j];
		int cnt = 0;
		FOR(i, h)FOR(j, w)if (c[i][j] == 1) {
			search(j, i);
			cnt++;
		}
		cout <<"   "<< cnt << endl;
	}
	

	return 0;
}

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

#define int long long

int w, h;
int field[51][51];

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

void dfs(int x, int y) {
    field[x][y] = 0;
    for(int i=0; i<8; ++i) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if(nx>=0&&nx<h&&ny>=0&&ny<w&&field[nx][ny]==1) dfs(nx, ny);
    }
}

signed main()
{
    while(cin>>w>>h, w) {
        for(int i=0; i<h; ++i)
            for(int j=0; j<w; ++j) field[i][j] = 0;
        for(int i=0; i<h; ++i) {
            for(int j=0; j<w; ++j) {
                cin >> field[i][j];
            }
        }

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

        cout << ans << endl;
    }
    return 0;
}

C++: 
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>

using namespace std;

int H, W, m[55][55], dx[] = {1,1,0,-1,-1,-1,0,1}, dy[] = {0,1,1,1,0,-1,-1,-1};
bool flag[55][55];

void dfs(int y, int x) {
	for (int k = 0; k < 8; k++) {
		int nx = x + dx[k] , ny = y + dy[k];
		if (0<=ny && ny<H && 0<=nx && nx<W) {
			if (flag[ny][nx] && m[ny][nx]==1) {
				flag[ny][nx] = false;
				dfs(ny, nx);
			}
		}
	}
}

int main() {
	
	while (1) {

		cin >> W >> H;
		if (W==0 && H==0) break;
	
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++) {
				cin >> m[i][j];
				flag[i][j] = true;
			}
		}

		int cnt = 0;
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++) {
				if (m[i][j] == 1 && flag[i][j]) cnt++;
				flag[i][j] = false;
				if(m[i][j]==1) dfs(i, j);
			}
		}

		cout << cnt<<endl;

	}
	return 0;
}

C++: #include <stdio.h>
int i,j,RB[51][51],N,M,ans,a[8][2]={-1,0,1,0,0,-1,0,1,-1,-1,-1,1,1,-1,1,1};void bfs(int x, int y) {RB[x][y]=0;for (int q=0,nx,ny;q<8;q++) {nx=x+a[q][0],ny=y+a[q][1];if (nx>=0 && nx<N && ny>=0 && ny<M && RB[nx][ny]) bfs(nx,ny);}}
int main() {while (1) {scanf("%d %d",&M,&N);if (!N && !M) return 0;ans=0;for (i=0;i<N;i++) for (j=0;j<M;scanf("%d",&RB[i][j++]));for (i=0;i<N;i++) for (j=0;j<M;j++) if (RB[i][j]) bfs(i,j),ans++;printf("%d\n",ans);}}