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 <cstring>
using namespace std;

int M[52][52];

void fill(int y, int x){
	M[y][x] = 0;
	if(M[y-1][x]) fill(y-1,x);
	if(M[y+1][x]) fill(y+1,x);
	if(M[y][x-1]) fill(y,x-1);
	if(M[y][x+1]) fill(y,x+1);
	if(M[y-1][x-1]) fill(y-1,x-1);
	if(M[y+1][x-1]) fill(y+1,x-1);
	if(M[y-1][x+1]) fill(y-1,x+1);
	if(M[y+1][x+1]) fill(y+1,x+1);
}

main(){
	int w,h,c,i,j;
	while(cin>>w>>h,w){
		memset(M, 0, sizeof(M));
		c=0;
		for(i=1;i<=h;i++){
		for(j=1;j<=w;j++){
			cin >> M[i][j];
		}
		}
		for(i=1;i<=h;i++){
		for(j=1;j<=w;j++){
			if(!M[i][j]) continue;
			fill(i, j);
			c ++;
		}
		}
		
		cout << c << endl;
	}
}

C++: #include <bits/stdc++.h>
#define r(i,n) for(int i = 0; i<n; i++)
typedef long long ll;
using namespace std;
typedef pair<int,int> P;

int w,h,sum=0,umi[52][52];

int kesi(int a,int b){
  umi[a][b]=0;
  for(int dx=-1;dx<=1;dx++){
    for(int dy=-1;dy<=1;dy++){
      if(umi[a+dx][b+dy]==1){
        kesi(a+dx,b+dy);
      }
    }
  }
  return 0;
}

int main(){
  while(cin >> w >> h&&w&&h){
    r(i,h){
      r(j,w){
        cin >> umi[i][j];
      }
    }
    r(i,h){
      r(j,w){
        if(umi[i][j]==1){
          sum++;
          kesi(i,j);
        }
      }
    }
    cout<<sum<<endl;
    sum=0;
  }
}

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

using namespace std;

	ifstream fin;
	ofstream fout;

	//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp

	int gomi = 0;

	int a[52][52] = {};
	void check(int, int);

	int main(){

		fin.open("input.txt");
		fout.open("output.txt");

		int width = 0, height = 0;
		int count = 0;

		while (true){

			cin >> width >> height;
			if (width == 0 && height == 0)break;

			//初期化
			count = 0;
			for (int i = 0; i < 50; i++)
				for (int j = 0; j < 50; j++)
					a[i + 1][j + 1] = 0;

			for (int i = 0; i < height; i++)
				for (int j = 0; j < width; j++)
					cin >> a[i + 1][j + 1];

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					if (a[i + 1][j + 1] == 1){
						check(i + 1, j + 1);
						count++;
					}
				}
			}
			cout << count << endl;
			fout << count << endl;
		}
	}

	void check(int y, int x){
		for (int i = -1; i <= 1; i++)
			for (int j = -1; j <= 1; j++)
				if (i + j != 0 || i - j != 0)
					if (a[y + i][x + j] == 1){
			a[y + i][x + j] = 0;
			check(y + i, x + j);
					}
	}
//------------------------------------------------------------↑↓どちらでもいい------------------------------------------------------------
/*	void check(int y, int x){
		if (a[y + 1][x] == 1){
			a[y + 1][x] = 0;
			check(y + 1, x);
		}
		//-----------------------------
		if (a[y][x + 1] == 1){
			a[y][x + 1] = 0;
			check(y, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x] == 1){
			a[y - 1][x] = 0;
			check(y - 1, x);
		}
		//-----------------------------
		if (a[y][x - 1] == 1){
			a[y][x - 1] = 0;
			check(y, x - 1);
		}
		//-----------------------------
		if (a[y + 1][x + 1] == 1){
			a[y + 1][x + 1] = 0;
			check(y + 1, x + 1);
		}
		//-----------------------------
		if (a[y + 1][x - 1] == 1){
			a[y + 1][x - 1] = 0;
			check(y + 1, x - 1);
		}
		//-----------------------------
		if (a[y - 1][x + 1] == 1){
			a[y - 1][x + 1] = 0;
			check(y - 1, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x - 1] == 1){
			a[y - 1][x - 1] = 0;
			check(y - 1, x - 1);
		}
		//-----------------------------
	}*/

C++: #include<iostream>
#include <malloc.h>
#include <vector>
using namespace std;

void search(int i,int j,int **c,int h,int w){
  c[i][j] = 0;
  if(j<w-1 && c[i][j+1]==1) search(i,j+1,c,h,w);
  if(i<h-1 && c[i+1][j]==1) search(i+1,j,c,h,w);

  if(j>0 && i<h-1 && c[i+1][j-1]==1) search(i+1,j-1,c,h,w);
  if(j<w-1 && i>0 && c[i-1][j+1]==1) search(i-1,j+1,c,h,w);
  if(j>0 && i>0 && c[i-1][j-1]==1) search(i-1,j-1,c,h,w);
  if(j<w-1 && i<h-1 && c[i+1][j+1]==1) search(i+1,j+1,c,h,w);
  if(i>0 && c[i-1][j]==1) search(i-1,j,c,h,w);
  if(j>0 && c[i][j-1]==1) search(i,j-1,c,h,w);
}

int main(){
  vector<int> vec;
  while(1){
    int w,h;
    cin >> w >> h;
    if(w==0 && h==0) break;
    int **c = (int**)malloc(sizeof(int*)*h);
    for(int i=0;i<h;i++){
        c[i] = (int*)malloc(sizeof(int*)*w);
        for(int j=0;j<w;j++) cin >> c[i][j];
    }
    int count = 0;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
        if(c[i][j]==1){
          count += 1;
          search(i,j,c,h,w);
        }
      }
    }
    //cout << count << endl;
    vec.push_back(count);
    for(int i=0;i<h;i++){
        free(c[i]);
    }
    free(c);
  }
  int n = vec.size();
  for(int i=0;i<n;i++) cout << vec[i] << endl;
  return 0;
}

C++: #include <bits/stdc++.h>

#define REP(i, n) for(int (i)=0; (i)<(n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define INF 1e9

using namespace std;
typedef pair<int, int> pii;

int w, h;
int m[50][50];
int dx[8] = {1, 1, 1, 0, 0, -1, -1, -1};
int dy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(int nw, int nh){
  REP(i, 8){
    if(nw + dx[i] < 0 or nw + dx[i] >= w or nh + dy[i] < 0 or nh + dy[i] >= h) continue;
    if(m[nw+dx[i]][nh+dy[i]] == 1) { m[nw+dx[i]][nh+dy[i]] = 0; dfs(nw+dx[i], nh+dy[i]); }
  }
  return;
}

int main(){
  while(cin >> w >> h and w + h){
    int res = 0;
    REP(i, h) REP(j, w) cin >> m[j][i];
    REP(i, h) REP(j, w) { if(m[j][i]) { dfs(j, i); res++; } }
    cout << res << endl;
  }
  return 0;
}

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

using namespace std;

void sink(int i, int j,int w,int h, int** field);

int main() {
	int w, h;
	int** field;
	while (1) {
		cin >> w >> h;
		if (w == 0)break;
		field = new int* [h];
		for (int i = 0;i < h;i++) {
			field[i] = new int[w];
			for (int j = 0;j < w;j++) {
				cin >> field[i][j];
			}
		}
		int cnt = 0;
		for (int i = 0;i < h;i++) {
			for (int j = 0;j < w;j++) {
				if (field[i][j]) {
					cnt++;
					sink(i, j,w,h, field);
				}
			}
		}
		cout << cnt << endl;
	}
}

void sink(int i, int j,int w,int h, int** field) {
	field[i][j] = 0;
	if (i > 0) {
		if (field[i - 1][j])sink(i - 1, j, w, h, field);
	}
	if (i < h-1) {
		if (field[i + 1][j])sink(i + 1, j, w, h, field);
	}
	if (j > 0) {
		if (field[i][j-1])sink(i , j-1, w, h, field);
	}
	if (j < w-1) {
		if (field[i][j+1])sink(i , j+1, w, h, field);
	}
	if (i > 0 && j > 0) {
		if (field[i - 1][j - 1])sink(i - 1, j - 1, w, h, field);
	}
	if (i > 0 && j < w - 1) {
		if (field[i - 1][j + 1])sink(i - 1, j + 1, w, h, field);
	}
	if (i < h-1 && j > 0) {
		if (field[i + 1][j - 1])sink(i + 1, j - 1, w, h, field);
	}
	if (i < h-1 && j < w-1) {
		if (field[i + 1][j + 1])sink(i + 1, j + 1, w, h, field);
	}
}