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<queue>
#include<cstdio>

#define	mp	make_pair

using namespace std;

typedef	pair<int,int>	pii;

const int dx[]={1,1,0,-1,-1,-1,0,1},dy[]={0,-1,-1,-1,0,1,1,1};
int field[50][50];
bool visited[50][50];

int main(){
	for(int w,h;scanf("%d%d",&w,&h),w;){
		for(int i=0;i<h;i++)for(int j=0;j<w;j++){
			scanf("%d",field[i]+j);
			visited[i][j]=false;
		}

		int cnt=0;
		for(int i=0;i<h;i++)for(int j=0;j<w;j++){
			if(field[i][j]==1 && !visited[i][j]){
				visited[i][j]=true;
				queue<pii> qu;	qu.push(mp(i,j));
				while(!qu.empty()){
					pii a=qu.front();	qu.pop();
					for(int k=0;k<8;k++){
						int xx=a.second+dx[k],yy=a.first+dy[k];
						if(0<=xx && xx<w && 0<=yy && yy<h
						&& field[yy][xx]==1 && !visited[yy][xx]){
							qu.push(mp(yy,xx));
							visited[yy][xx]=true;
						}
					}
				}
				cnt++;
			}
		}

		printf("%d\n",cnt);
	}

	return 0;
}

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

int H, W;
vector<vector<int>> field;
void dfs(int h, int w) {
    field[h][w] = 0;
    for(int dh = -1; dh <= 1; dh++) {
        for(int dw = -1; dw <= 1; dw++) {
            int nh = h + dh;
            int nw = w + dw;
            if(nh < 0 || H <= nh || nw < 0 || W <= nw) {
                continue;
            }
            if(field[nh][nw] == 0) {
                continue;
            }
            dfs(nh, nw);
        }
    }
}
int main() {
    while (cin >> W >> H) {
        if (H == 0 || W == 0) break;
        field.assign(H, vector<int>(W, 0));
        for (int h = 0; h < H; ++h) for (int w = 0; w < W; ++w) cin >> field[h][w];

        // 探索開始
        int count = 0;
        for (int h = 0; h < H; ++h) {
            for (int w = 0; w < W; ++w) {
                if (field[h][w] == 0) continue; // 残島じゃなかったらスルー
                dfs(h, w);
                ++count;
            }
        }
        cout << count << endl;
    }
}

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

const int dx[] = { 0, 1, 0,-1, 1, 1,-1,-1};
const int dy[] = {-1, 0, 1, 0,-1, 1, 1,-1};

int main() {
    int Map[100][100];
    while(true)
    {
        int w, h;
        cin >> w >> h;
        if(w == 0 && h == 0) break;

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

        // 左上からラスタ走査
        int res = 0;
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                if(Map[i][j] == 1) {
                    ++res;
                    queue<pair<int,int>> que;
                    que.push(make_pair(i,j));
                    Map[i][j] = 0;
                    while(!que.empty()){
                        int x = que.front().first;
                        int y = que.front().second;
                        que.pop();
                        for(int k = 0; k < 8; ++k) {
                            int nx = x + dx[k];
                            int ny = y + dy[k];
                            if(nx < 0 || nx >= h || ny < 0 || ny >= w) continue;
                            if(Map[nx][ny] == 1) {
                                que.push(make_pair(nx, ny));
                                Map[nx][ny] = 0;
                            }
                        }
                    }
                    
                }
            }
        }
        cout << res << endl;
    }
    return 0;
}

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); }

int prime[25] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
long long int dp[101][20] = {0};

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() {
    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>
#include <vector>

using namespace std;

inline bool inRange(int a, int x, int b) {
    return a <= x && x < b;
}

void fill(vector<vector<int> > &v, int r, int c) {
    v[r][c] = 0;
    for(int dr = -1; dr <= 1; ++dr) {
        for(int dc = -1; dc <= 1; ++dc) {
            int nr = r + dr;
            int nc = c + dc;
            if(inRange(0, nr, v.size()) && inRange(0, nc, v[0].size()) && v[nr][nc]) {
                fill(v, nr, nc);
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(0);

    while(true) {
        int C, R;
        cin >> C >> R;
        if(!C && !R) break;

        vector<vector<int> > v(R, vector<int>(C));
        for(int i = 0; i < R; ++i) 
            for(int j = 0; j < C; ++j)
                cin >> v[i][j];

        int cnt = 0;
        for(int r = 0; r < R; ++r) {
            for(int c = 0; c < C; ++c) {
                if(v[r][c]) {
                    ++cnt;
                    fill(v, r, c);
                }
            }
        }

        //cout << cnt << endl;
    }

    return 0;
}