Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

		route = make([][]int, h+2)
		route[0] = make([]int, w+2)
		for i := 1; i <= h; i++ {
			route[i] = make([]int, w+2)
			for j := 1; j <= w; j++ {
				route[i][j] = scanInt()
			}
		}
		route[h+1] = make([]int, w+2)

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

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);
	}
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int W, H;
int c[50][50];
bool visited[50][50];
int vy[8] = {-1,-1,0,1,1,1,0,-1};
int vx[8] = {0,1,1,1,0,-1,-1,-1};
void calc(int y, int x) {
  if(y < 0 || y >= H || x < 0 || x >= W) return;
  if(visited[y][x] || c[y][x] == 0) return;
  visited[y][x] = true;
  FOR(i,0,8) calc(y+vy[i],x+vx[i]);
  return;
}
int main()
{
  while(cin >> W >> H, (W || H)) {
    CLR(visited);
    FOR(y,0,H) FOR(x,0,W) cin >> c[y][x];
    int ans = 0;
    FOR(y,0,H) {
      FOR(x,0,W) {
        if(visited[y][x] || c[y][x] == 0) continue;
        calc(y, x);
        ans++;
      }
    }
    cout << ans << endl;
  }
  return 0;
}