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 <cstdio>
#include <utility>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <iomanip>
#include <vector>
#include <string>
#define REP(i,n) for(int i=0;i<n;i++)
typedef long long ll;
using namespace std;
typedef vector<ll> vl;
typedef pair<ll,ll> pll;
typedef vector<pll> vpll;
typedef vector<string> vs;

int main() 
{
	
	int w,h;
	while(cin >> w >> h && !(w==0&&h==0))
	{
		int a[50][50]={};
		REP(i,h){REP(j,w){cin >> a[j][i];}}
		
		int id = 10; //島のid 初期値は適当
		
		//w=0の時
		if(a[0][0]!=0){a[0][0]=id;}
		for(int i=1;i<h;i++){
			if(a[0][i]!=0 && a[0][i-1]==0){id++;a[0][i]=id;}
			else if(a[0][i]!=0){a[0][i]=a[0][i-1];}
		}
		//w>0の時
		for(int i=1;i<w;i++)
		{
			//h=0の時
			if(a[i][0]!=0){
				if(a[i-1][0]!=0 || a[i-1][1]!=0){a[i][0]=max(a[i-1][0],a[i-1][1]);}
				else{id++;a[i][0]=id;}
			}
			//h>0の時
			for(int j=1;j<h;j++)
			{
				if(a[i][j]!=0)
				{
					int tmp = max(a[i][j-1],a[i-1][j-1]);
					tmp = max(tmp,a[i-1][j]);
					tmp = max(tmp,a[i-1][j+1]);
					if(tmp==0){id++;a[i][j]=id;}
					else{
						a[i][j] = tmp;
						int tmp1,tmp2,tmp3,tmp4;
						tmp1=a[i][j-1];
						tmp2=a[i-1][j-1];
						tmp3=a[i-1][j];
						tmp4=a[i-1][j+1];
						if(a[i][j-1]!=0 && a[i][j-1]!=tmp){REP(k,w){REP(l,h){if(a[k][l]==tmp1)a[k][l]=tmp;}}}
						if(a[i-1][j-1]!=0 && a[i-1][j-1]!=tmp){REP(k,w){REP(l,h){if(a[k][l]==tmp2)a[k][l]=tmp;}}}
						if(a[i-1][j]!=0 && a[i-1][j]!=tmp){REP(k,w){REP(l,h){if(a[k][l]==tmp3)a[k][l]=tmp;}}}
						if(a[i-1][j+1]!=0 && a[i-1][j+1]!=tmp){REP(k,w){REP(l,h){if(a[k][l]==tmp4)a[k][l]=tmp;}}}
					}
				}
			}
		}
		int b[2500]={};
		REP(i,w){REP(j,h){b[i+w*j]=a[i][j];}}
		sort(b,b+h*w);
		reverse(b,b+h*w);
		
		int ans(0);
		if(b[0]>1){ans++;}
		for(int i=1;i<w*h;i++){if(b[i]!=b[i-1] && b[i]>1)ans++;}
		
		cout << ans << endl;
	}
	return 0;
}

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

#define W 50
#define H 50

using namespace std;
void dfs(int w, int h);
int map[H][W];
int dy[8] = {1,1,0,-1,-1,-1,0,1}, dx[8] = {0,-1,-1,-1,0,1,1,1};
int w,h;

int main(){
  int i = 0,j = 0,is=0;
  cin >> w >> h;

  while(w != 0 && h != 0){
    for(i = 0;i < h;i++){
      for(j = 0;j<w;j++){
	cin>>map[i][j];
      }
    }
    i = j = 0;
    is = 0;
    while(i <= h-1  && j <= w-1){
      if(map[i][j] == 1){
	dfs(i,j);
	is++;
      }
      i++;
      if(i == h){
	i = 0;
	j++;
      }
    }
    cout << is << endl;
    cin >> w >> h;
  }
  return 0;
}

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

C++: #include <iostream>

using namespace std;

const int MAX_LENGTH = 50;

int map[MAX_LENGTH][MAX_LENGTH];

void dfs(int x, int y) {
	for (int i = -1; i <= 1; i++) {
		for (int j = -1; j <= 1; j++) {
			if (y + i >= 0 && MAX_LENGTH > y + i && x + j >= 0 && MAX_LENGTH > x + j && map[y+i][x+j] == 1) {
				map[y+i][x+j] = 0;
				dfs(x + j, y + i);
			}
		}
	}

	return;
}

int main() {
	while (true) {
		int w, h, count;
		cin >> w >> h;
		if (w == 0) {
			break;
		}
		for (int i = 0; i < MAX_LENGTH; i++) {
			for (int j = 0; j < MAX_LENGTH; j++) {
				map[i][j] = 0;
			}
		}
		
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> map[i][j];
			}
		}
		
		count = 0;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (map[i][j] == 1) {
					map[i][j] = 0;
					dfs(j, i);
					count++;
					/*
					for (int k = 0; k < h; k++) {
						for (int l = 0; l < w; l++) {
							cout << map[k][l] << " ";
						}
						cout << endl;
					}
					cout << endl;
					*/
				}
			}
		}
		cout << count << endl;
	}

	return 0;
}

C++: #include<algorithm>
#include<bitset>
#include<iostream>
#include<iomanip>
#include<set>
#include<string>
#include<math.h>

using namespace std;

class zahyo{
	public:
	int x;
	int y;
	zahyo(){
		x=0;
		y=0;
	}
	zahyo(int x_,int y_){
		x=x_;
		y=y_;
	}
	void print(){
		cout<<x<<" "<<y;
	}
	zahyo operator+(zahyo add){
		add.x=this->x+add.x;
		add.y=this->y+add.y;
		return add;
	}
	zahyo operator-(zahyo add){
		add.x=this->x-add.x;
		add.y=this->y-add.y;
		return add;
	}
	bool operator==(const zahyo add) const{
		if(add.x==this->x and add.y==this->y){return true;}
		else{return false;}
	}
	bool operator!=(const zahyo add) const{
		if(add.x==this->x or add.y==this->y){return false;}
		else{return true;}
	}
	bool operator<(const zahyo add) const{
		if(this->x<add.x){return true;}
		else if(this->x==add.x and this->y<add.y){return true;}
		else{return false;}
	}
	bool operator>(const zahyo add) const{
		if(this->x>add.x){return true;}
		else if(this->x==add.x and this->y>add.y){return true;}
		else{return false;}
	}
	void input(){
		cin>>x>>y;
	}
};

int n;
int counter=0;
int field[50][50]={{}};
int arrived[50][50]={{}};
int ways[8][2]={{1,1},{1,0},{1,-1},{0,-1},{-1,-1},{-1,0},{-1,1},{0,1}};
int h,w;
void depthsearch(int h_,int w_){
	arrived[h_][w_]=1;
	for(int i=0;i<8;i++){
		int newh=h_+ways[i][0];
		int neww=w_+ways[i][1];
		if(newh>=0 and newh<h and neww>=0 and neww<w){
			if(arrived[newh][neww]==0 and field[newh][neww]==1){
				depthsearch(newh,neww);
			}
		}
	}
}

int main(){

	while(1){
		cin>>w>>h;
		if(w==0 and h==0){break;}
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin>>field[i][j];
				arrived[i][j]=0;
			}
		}
		int ans=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(arrived[i][j]==0 and field[i][j]==1){
					depthsearch(i,j);
					ans++;
				}
			}
		}
		cout<<ans<<endl;
	}
}

C++: #include <iostream>
using namespace std;

void proc(int *maps,int p,int w,int h){
	if(maps[p]==1) maps[p]=2;
	else return;
	int x=p%w;
	int y=p/w;
	for(int i=-1;i<=1;++i){
		for(int j=-1;j<=1;++j){
			int nx=x+j;
			int ny=y+i;
			if(nx>=0&&ny>=0&&nx<w&&ny<h){
				proc(maps,nx+ny*w,w,h);
			}
		}
	}
}

int main(void){
	int w,h;
	while(cin>>w>>h,w&&h){
		int chizu[2500];
		for(int i=0;i<h;++i){
			for(int j=0,a;j<w;++j){
				cin>>a;
				chizu[i*w+j]=a;
			}
		}
		int count = 0;
		for(int i=0;i<w*h;++i){
			if(chizu[i]==1){
				proc(chizu,i,w,h);
				++count;
			}
		}
		cout<<count<<endl;
	}
	return 0;
}

C++: #include <iostream>

using namespace std;

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

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

int main(){
	while(cin >> w >> h, 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++, dfs(i,j);
		cout << ans << endl;
	}
}