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 <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <functional>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>

using namespace std;

inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string toString(T x) { ostringstream sout; sout << x; return sout.str();}

typedef vector<int> vi;
typedef vector<vi>  vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EACH(t,i,c) for(t::iretator i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

const double EPS = 1e-10;

int seamap[52][52];
static int num = 0;

void dfs(int x, int y) {
	if(seamap[x][y] == 1) {

	if(seamap[x-1][y-1]) {
		seamap[x-1][y-1] = 0;
		dfs(x-1, y-1);
	}
	else if(seamap[x][y-1]) {
		seamap[x][y-1] = 0;
		dfs(x, y-1);
	}
	else if(seamap[x+1][y-1]) {
		seamap[x+1][y-1] = 0;
		dfs(x+1, y-1);
	}
	else if(seamap[x-1][y]) {
		seamap[x-1][y] = 0;
		dfs(x-1, y);
	}
	else if(seamap[x+1][y]) {
		seamap[x+1][y] = 0;
		dfs(x+1, y);
	}
	else if(seamap[x-1][y+1]) {
		seamap[x-1][y+1] = 0;
		dfs(x-1, y+1);
	}
	else if(seamap[x][y+1]) {
		seamap[x][y+1] = 0;
		dfs(x, y+1);
	}
	else if(seamap[x+1][y+1]) {
		seamap[x+1][y+1] = 0;
		dfs(x+1, y+1);
	}
	else {
		++num;
	}

	}
}


int main() {
	int w, h;

	REP(i, 52) {
		REP(j, 52) {
			seamap[i][j] = 0;
		}
	}

	while(cin >> w >> h, (w!=0 && h!=0)) {
		FOR(i, 1, h+1) {
			FOR(j, 1, w+1) {
				int p;
				cin >> p;
				seamap[i][j] = p;
			}
		}

		FOR(i, 1, h+1) {
			seamap[i][w+1] = 0;
		}

		FOR(j, 1, w+1) {
			seamap[h+1][j] = 0;
		}
	
		num = 0;

		FOR(i, 1, 50) {
			FOR(j, 1, 50) {
				dfs(i, j);
			}
		}

		cout << num << endl;
	}
}

C++: #include <iostream>

#include <string>
#include <queue>

using namespace std;

int main(){
	int w,h;
	int data[60][60];
	int flag[60][60];
	int dx[8] ={-1,-1,-1,0,1,1,1,0};
	int dy[8] ={-1,0,1,1,1,0,-1,-1};

	while(1){
		cin>>w>>h;
		if(w==0 && h==0)break;

	for(int i=0;i<60;i++){
		for(int j=0;j<60;j++){
			data[i][j]=-1;
			flag[i][j]=0;
		}
	}

	char tmp;
	int startX;
	int startY;
	int cnt=0;

	for(int i=1;i<=h;i++){
		for(int j=1;j<=w;j++){
			cin>>tmp;
			if(tmp=='1')data[i][j] = 0;
		}
	}

	queue<int> qX,qY;
	
	for(int i=1;i<=h;i++){
		for(int j=1;j<=w;j++){
			if(data[i][j]==0 && flag[i][j]==0){
				flag[i][j]=1;
				qX.push(j);
				qY.push(i);
				cnt++;
			}
			else continue;

			while(qX.size()!=0){
				int topX = qX.front();
				int topY = qY.front();
				qX.pop();
				qY.pop();

				for(int i=0;i<8;i++){
					int nowX = topX + dx[i];
					int nowY = topY + dy[i];

					if(data[nowY][nowX] ==0 && flag[nowY][nowX] == 0){
						qX.push(nowX);
						qY.push(nowY);
						flag[nowY][nowX]=1;
					}
				}
			}
		}
	}

	cout<<cnt<<endl;
	}

	return 0;
}

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

int w, h;

void dfs(int hh, int ww, vector<vector<int>> &c, vector<vector<bool>> &seen)
{
    int dh[8] = {1, 1, 1, 0, 0, -1, -1, -1};
    int dw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
    seen[hh][ww] = true;
    for (int i = 0; i < 8; i++)
    {
        int hhh = hh + dh[i];
        int www = ww + dw[i];
        if (hhh < 1 || hhh > h || www < 1 || www > w)
        {
            continue;
        }
        if (c[hhh][www] == 0)
        {
            continue;
        }
        if (seen[hhh][www])
        {
            continue;
        }
        dfs(hhh, www, c, seen);
    }
}

int main()
{
    vector<int> ans;
    while (1)
    {
        cin >> w >> h;
        if (w == 0 && h == 0)
            break;
        vector<vector<int>> c(h + 1, vector<int>(w + 1));
        vector<vector<bool>> seen(h + 1, vector<bool>(w + 1, false));
        for (int i = 1; i <= h; i++)
        {
            for (int j = 1; j <= w; j++)
            {
                cin >> c[i][j];
                if (c[i][j] == 0)
                {
                    seen[i][j] = true;
                }
            }
        }
        int count = 0;
        for (int i = 1; i <= h; i++)
        {
            for (int j = 1; j <= w; j++)
            {
                if (seen[i][j] || c[i][j] == 0)
                    continue;
                dfs(i, j, c, seen);
                count++;
            }
        }
        ans.push_back(count);
    }
    for (int i : ans)
    {
        cout << i << endl;
    }
}

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] = {};
	int check(int, int);

	int main(){

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

		//		int w = 0, h = 0;
		int width = 0, height = 0;
		int count = 0;


		while (1){
			for (int i = 0; i < 50; i++)
				for (int j = 0; j < 50; j++)
					a[i + 1][j + 1] = 0;

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

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					//初期化
					gomi = a[i + 1][j + 1] = 0;

					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);
//						a[i + 1][j + 1] = 1;
						count++;
					//	cout << i + 1 << "  " << j + 1 << endl;
					}
				}
			}
//			cout << count << endl;
			fout << count << endl;

			//初期化
			count = 0;
			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					a[i + 1][j + 1] = 0;
				}
			}
		}
	}

	int check(int y, int x){
		for (int i = -1; i <= 1; i++)
			for (int j = -1; j <= 1; j++){
			if (i == 0 && j == 0)
				j++;
			check(y + i, x + j);
			}
	return 0;
	}

/*	int 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);
		}
		//-----------------------------
		return 0;
	}*/