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 <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) FOR(i,0,n)
#define repr(i,n) for(int i=(n)-1;0<=i;--i)
#define each(e,v) for(auto&& e:(v))
#define all(v) begin(v),end(v)
#define dump(x) cerr<<#x<<": "<<(x)<<endl
#define INF 100000000
#define IINF 9999999999999;
using vint = vector<int>;
using ll = long long;
using vll = vector<ll>;
template <class T> void chmin(T& a, const T& b) { a = min(a, b); }
template <class T> void chmax(T& a, const T& b) { a = max(a, b); }

bool earth[51][51];

void erase_island(int h, int w) {
    earth[h][w] = false;
    //cout << "# " << h << " " << w << endl;
    if(earth[h - 1][w - 1]) erase_island(h - 1, w - 1);
    if(earth[h - 1][w]) erase_island(h - 1, w);
    if(earth[h - 1][w + 1]) erase_island(h - 1, w + 1);
    if(earth[h][w + 1]) erase_island(h, w + 1);
    if(earth[h + 1][w + 1]) erase_island(h + 1, w + 1);
    if(earth[h + 1][w]) erase_island(h + 1, w);
    if(earth[h + 1][w - 1]) erase_island(h + 1, w - 1);
    if(earth[h][w - 1]) erase_island(h, w - 1);
}

int main() {
    //ofstream outputfile("output.txt");
    while(true) {
        int w, h;
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        rep(i, h) rep(j, w) {
                int temp;
                cin >> temp;
                if(temp == 0) earth[i][j] = false;
                else earth[i][j] = true;
            }

        int ans = 0;
        rep(i, h) rep(j, w) {
                if(earth[i][j]) erase_island(i , j), ++ans;
            }

        cout << ans << endl;
    }

    return 0;
}

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

int myMap[50][50];
int w, h;
int ans;

bool safe(int x, int y){
    return (0 <= x && 0 <= y) && (x < h && y < w);
}

void del(int x, int y){
    myMap[x][y] = 0;
    if (safe(x+1, y) && myMap[x+1][y]) del(x+1, y);
    if (safe(x+1, y+1) && myMap[x+1][y+1]) del(x+1, y+1);
    if (safe(x+1, y-1) && myMap[x+1][y-1]) del(x+1, y-1);
    if (safe(x, y+1) && myMap[x][y+1]) del(x, y+1);
    if (safe(x, y-1) && myMap[x][y-1]) del(x, y-1);
    if (safe(x-1, y-1) && myMap[x-1][y-1]) del(x-1, y-1);
    if (safe(x-1, y+1) && myMap[x-1][y+1]) del(x-1, y+1);
    if (safe(x-1, y) && myMap[x-1][y]) del(x-1, y);
    return;
}

int main(){

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

	for (int i = 0; i < h; i++){
	    for (int j = 0; j < w; j++){
		cin >> myMap[i][j];
	    }
	}

	ans = 0;	
	for (int i = 0; i < w; i++){
	    for (int j = 0; j < h; j++){
		if (myMap[i][j] == 1){
		    ans++;
		    del(i, j);
		}
	    }
	}

	cout << ans << endl;
    }
}

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) {
		seamap[x][y] = 0;

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


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) {
				if(seamap[i][j]) {
					num++;
					dfs(i, j);
				}
			}
		}

		cout << num << endl;
	}
}

C++: #include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<algorithm>
#include <functional>

using namespace std;

int INF = 10000000;

bool f[50][50];
bool cell[50][50];
int w,h;

int dfs(int i,int j)
{
	if(i < 0 || j < 0 || i >= h || j >= w || f[i][j])return 0;

	if(!cell[i][j])return 0;

	f[i][j] = true;

	dfs(i-1,j);
	dfs(i+1,j);
	dfs(i,j+1);
	dfs(i,j-1);
	
	dfs(i-1,j-1);
	dfs(i-1,j+1);
	dfs(i+1,j-1);
	dfs(i+1,j+1);

	return 1;
}

int cast()
{
	int sum = 0;
	for(int i = 0;i < h;i++)
	{
		for(int j = 0;j < w;j++)
		{
			sum += dfs(i,j);
		}
	}
	return sum;
}



int main()
{

	while(1)
	{
		cin >> w >> h;

		if(!w && !h)break;

		memset(f,0,50*50*sizeof(bool));
		memset(cell,0,50*50*sizeof(bool));

		for(int i = 0;i < h;i++)
		{
			for(int j = 0;j < w;j++)
			{
				cin >> cell[i][j];
			}
		}

		cout << cast() << endl;
	
	}

  return 0;
}

C++: #include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <functional>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vec;
typedef pair<int, int> P;
#define rep(n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define out(a) cout << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
#define INF 100000000

int w, h;
int f[55][55] = { 0 };

void dfs(int y, int x) {
	for (int i = -1; i <= 1; i++) {
		for (int j = -1; j <= 1; j++) {
			int ny = y + i;
			int nx = x + j;
			if (0 <= ny&&ny < h && 0 <= nx&&nx < w&&f[ny][nx] == 1) {
				f[ny][nx] = 0;
				dfs(ny, nx);
			}
		}
	}
	return;
}

int main() {
	while (true) {
		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 >> f[i][j];
			}
		}
		int res = 0;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (f[i][j] == 1) {
					f[i][j] = 0;
					res++;
					dfs(i, j);
				}
			}
		}
		cout << res << endl;
	}
	return 0;
}