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;
void kazoeruyo(int p,int P,int box[50][50]){
  box[p][P]=0;
    if(box[p][P+1]==1) {
      box[p][P+1]=0;
      P=P+1; 
      kazoeruyo(p,P,box);
    }
    if(box[p][P-1]==1){
      box[p][P-1]=0;
      P=P-1;
      kazoeruyo(p,P,box);
    }
    if(box[p+1][P]==1){ 
      box[p+1][P]=0;
      p=p+1;
      kazoeruyo(p,P,box);
    }
    if(box[p-1][P]==1){
      box[p-1][P]=0;
      p=p-1;
      kazoeruyo(p,P,box);
    }
    if(box[p-1][P-1]==1){
      box[p-1][P-1]=0;
      p=p-1;
      P=P-1;
      kazoeruyo(p,P,box);
    }
    if(box[p-1][P+1]==1){
      box[p-1][P+1]=0;
      p=p-1;
      P=P+1;
      kazoeruyo(p,P,box);
    }
    if(box[p+1][P+1]==1){
      box[p+1][P+1]=0;
      p=p+1;
      P=P+1;
      kazoeruyo(p,P,box);
    }
    if(box[p+1][P-1]==1){
      box[p+1][P-1]=0;
      p=p+1;
      P=P-1;
      kazoeruyo(p,P,box);
    }	
}
int main(){
  int w,h,i,I,p,P,o,t,T,y,Y;
  int box[50][50];
  while(1){
    cin>>w>>h;
    if(w==0&&h==0) break;
    for(i=0;i<h;i++){
      for(I=0;I<w;I++){
	cin>>box[i][I];
      }
    }
    o=0;
    for(i=0;i<h;i++){
      for(I=0;I<w;I++){
	if(box[i][I]==1) {
	  p=i;
	  P=I;
	  kazoeruyo(p,P,box);
	  box[p][P]=1;
	}
      }
    }
    for(i=0;i<h;i++){
      for(I=0;I<w;I++){
	if(box[i][I]==1) o++;
      }
    }
    cout<<o<<endl;
    o=0;
  }
  return 0;
}

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

using namespace std;

struct Node{

	Node();

	int aLandType;

};

Node::Node(){
	aLandType = 0;
}

bool check(const int x, const int y, const int LandNum, const int aNodeCol[50][50], const int aXMax, const int aYMax){
	if ((x<0 || x >= aXMax) || (y<0 || y >= aYMax) || (aNodeCol[x][y] != 1)){
		return false;
	}
	return true;
}
bool LandConfirmedAndMawariCheck(const int x, const int y, const int LandNum, int aNodeCol[50][50], const int aXMax, const int aYMax){
	if (aNodeCol[x][y] == 1){
		aNodeCol[x][y] = LandNum;
		/*if (check(x - 1, y, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x, y + 1, LandNum, aNodeCol, aXMax, aYMax);*/
		if (!(x - 1<0 || x - 1 >= aXMax) || (y    <0 || y     >= aYMax) || (aNodeCol[x-1][y    ] != 1))LandConfirmedAndMawariCheck(x - 1, y    , LandNum, aNodeCol, aXMax, aYMax);
		if (!(x - 1<0 || x - 1 >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x-1][y - 1] != 1))LandConfirmedAndMawariCheck(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x - 1<0 || x - 1 >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x-1][y + 1] != 1))LandConfirmedAndMawariCheck(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x+1][y - 1] != 1))LandConfirmedAndMawariCheck(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y    <0 || y     >= aYMax) || (aNodeCol[x+1][y    ] != 1))LandConfirmedAndMawariCheck(x + 1, y    , LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x+1][y + 1] != 1))LandConfirmedAndMawariCheck(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x    <0 || x     >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x  ][y - 1] != 1))LandConfirmedAndMawariCheck(x    , y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x    <0 || x     >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x  ][y + 1] != 1))LandConfirmedAndMawariCheck(x    , y + 1, LandNum, aNodeCol, aXMax, aYMax);
		return true;
	}
	return false;
}



int main(void){
	int NodeCol[50][50];
	int a, b, c;
	int XMax, YMax;
	while(1){
		cin >> a >> b;
		XMax = a; YMax = b;

		for (int Lone = 0;  Lone < XMax; ++Lone){
			for (int Ltwo = 0; Ltwo < YMax; ++Ltwo){
				cin >> c;
				NodeCol[Lone][Ltwo] = c;
			}
		}
		int t = 2;
		for (int Lone = 0;  Lone < XMax; ++Lone){
			for (int Ltwo = 0; Ltwo < YMax; ++Ltwo){
				if (NodeCol[Lone][Ltwo]==1)
				{
					if (LandConfirmedAndMawariCheck(Lone, Ltwo, t, NodeCol, XMax, YMax))t++;
				}
			}
		}
		cout << t-2;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int w,h;
int a[1000][1000];
int dx[8]={1,1,0,-1,-1,-1,0,1},dy[8]={0,1,1,1,0,-1,-1,-1};
void DFS(int x,int y){
    a[y][x]=0;
    for(int i=0;i<8;i++){
        int nx=x+dx[i];
        int ny=y+dy[i];
        if(nx>=0 && nx<w && ny>=0 && ny<h && a[ny][nx]==1){
            DFS(nx,ny);
        }
    }
}
int main(void){
    int cnt;
    while(1){
        cnt=0;
        cin>>w>>h;
        if(w==0 && h==0){
            return 0;
        }
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                cin>>a[i][j];
            }
        }
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                if(a[i][j]==1){
                    cnt++;
                    DFS(j,i);
                }
            }
        }
        cout<<cnt<<endl;
    }
}