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;

using ll = long long;

class UnionFind {
public:
    vector<int> data;
    UnionFind(int size) : data(size, -1) { }
    bool connect(int x, int y) {
        x = root(x); y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
        data[x] += data[y]; data[y] = x;
        }
        return x != y;
    }
    bool same(int x, int y) {
        return root(x) == root(y);
    }
    int root(int x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    int size(int x) {
        return -data[root(x)];
    }
};
int dx[] = {1, 1, 1, 0, -1, -1, -1, 0};
int dy[] = {1, 0, -1, -1, -1, 0, 1, 1};

int main()
{
    int h,w;
    while(cin >> h >> w){
        if(h == 0)return 0;
        map<pair<int,int>, int> se;
        int cnt = 0;
        for(int x = 0;x < w;x++){
            for(int y = 0;y < h;y++){
                int c;cin >> c;
                if(c){
                    se[make_pair(x, y)] = cnt;
                    cnt++;
                }
            }
        }
        UnionFind Uni(cnt);
        for(auto a : se){
            int x = a.first.first;
            int y = a.first.second;
            for(int i = 0;i < 8;i++){
                if(se.find(make_pair(x + dx[i], y + dy[i])) != se.end()){
                    Uni.connect(a.second, se[make_pair(x + dx[i], y + dy[i])]);
                }
            }
        }
        set<int> s;
        for(int i = 0;i < cnt;i++){
            s.insert(Uni.root(i));
        }
        std::cout<<s.size()<<endl;
    }
}

C++: #include<iostream>
#include<vector>
using namespace std;
int needx[]={-1,0,1,0,1,1,-1,-1};
int needy[]={0,1,0,-1,1,-1,1,-1};
//??¶?????¨???false????????????true???????????¢??°//
bool land(int x,int y,vector<vector<bool> >& cango){
    if(cango[x][y]){
        cango[x][y]=false;
        for(int i=0;i<8;i++){
            int nextx=x+needx[i];
            int nexty=y+needy[i];
            if(cango[nextx][nexty])
                bool flag=land(nextx,nexty,cango);
            }
    return true;
     }else{
return false;
    }
}
int main(void){
    int input;
	int w,h;
	while(1){
cin>>w>>h;
if(h==0)break;
    vector<vector<bool> > cango(h+2,vector<bool>(w+2,false));
    for(int i=1;i<=h;i++){
        for(int j=1;j<=w;j++){
            cin >>input;
            if(input==1){
cango[i][j]=true;
            }
        }
    }
  
    int t=0;
for(int i=1;i<=w;i++){
    for(int j=1;j<=h;j++){
        if(land(i,j,cango)){
            t++;
        }
    }
}
cout <<t<<endl;
	}
return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
bool d[51][51];
int a,b,s,_x,_y,dx[8]={0,-1,-1,-1,0,1,1,1},dy[8]={1,1,0,-1,-1,-1,0,1};
#define r(z,x) for(int z=0;z<x;z++)
void bfs(int x,int y){
    if(0>x||x>=b||0>y||y>=a)return;
    d[x][y]=0;
    r(i,8)if(d[_x=x+dx[i]][_y=y+dy[i]])bfs(_x,_y);
}
int main(){
    while(cin>>a>>b,a||b){
        s=0;
        r(i,b)r(j,a)cin>>d[i][j];
        r(i,b)r(j,a)if(d[i][j])bfs(i,j),s++;
        cout<<s<<endl;
    }
}

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

int w, h;
bool map[50][50];
int dx[8] = { 1, 1, 0, -1, -1, -1, 0, 1 };
int dy[8] = { 0, 1, 1, 1, 0, -1, -1, -1 };
int ans = 0;

void solve(int x, int y){
	map[x][y] = 0;

	for (int i = 0; i < 8; i++){
		int X = x + dx[i];
		int Y = y + dy[i];
		if (0 <= X&&X < w && 0 <= Y&&Y < h&&map[X][Y] != 0) solve(X, Y);
	}
}

int main(){
	while (cin >> w >> h, w + h != 0){
		ans = 0;
		for (int y = 0; y < h; y++){
			for (int x = 0; x < w; x++){
				cin >> map[x][y];
			}
		}

		for (int y = 0; y < h; y++){
			for (int x = 0; x < w; x++){
				if (map[x][y] == 1){
					solve(x, y);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
int H,W,k[100][100],n[100][100],color=1,i,j,l,m,o,r;
int main(){while(true){memset(n,0,sizeof(n));r=0;cin>>H>>W;if(H==0){break;}for(i=0;i<H;i++){for(j=0;j<W;j++){cin>>k[i][j];}}
for(i=0;i<H;i++){for(j=0;j<W;j++){if(r==1){color++;}r=0;if(k[i][j]==1 && n[i][j]==0){n[i][j]=color;for(l=0;l<20;l++){
	for(m=0;m<H;m++){for(o=0;o<W;o++){if(n[m][o]==color){
		for(int p=-1;p<=1;p++){for(int q=-1;q<=1;q++){if(m-p>=0 && m-p<H){if(o-q>=0 && o-q<W){n[m][o]=color;r=1;}}}}
	}}}
}}}}
cout<<color<<endl;}
}

C++: #include "bits/stdc++.h"

using namespace std;
using ll = long long int;
using ullong = unsigned long long;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)
#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
//#define llint

#ifdef llint
#define int ll
static const int INF = numeric_limits<long long>::max();
#else
static const int INF = numeric_limits<int>::max();
#endif // llint
static const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };

int w, h;

void dfs(int x,int y,vector<vector<int>>& map) {
	map[y][x] = 0;
	//rep(y, h) {
	//	rep(x, w) {
	//		cout << map[y][x] << " ";
	//	}
	//	cout << endl;
	//}
	//cout << endl;
	//cout << "x : " << x << " y : " << y << endl;
	rep(i, 8) {
		int tx = x + dx[i];
		int ty = y + dy[i];
		//cout << "nx : " << tx << " ny : " << ty << endl;
		if (tx >= 0 and tx < map[0].size() and ty >= 0 and ty < map.size()) {
			if(map[ty][tx] == 1)
				dfs(tx, ty, map);
		}
	}
	return;
}

signed main() {
	ios::sync_with_stdio(true);
	while (true) {
		cin >> w >> h;
		if (w == 0 and h == 0) break;
		vector<vector<int>>  map(h);
		rep(i, h) {
			rep(j, w) {
				int x;
				cin >> x;
				map[i].pb(x);
			}
		}
		int ans = 0;
		rep(y,h){
			rep(x, w) {
				if (map[y][x] == 1) {
					dfs(x, y, map);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
using ll = long long;
using pint = pair<int,int>;

int w, h;
int field[55][55];

void dfs(int sh, int sw){
    for(int dx = -1; dx <= 1; dx++){
        for(int dy = -1; dy <= 1; dy++){
            int nh = sh + dx, nw = sw + dy;
            if(nh < 0 || h <= nh || nw < 0 || w <= nw) continue;
            if(field[nh][nw] == 0) continue;
            field[nh][nw] = 0;
            dfs(nh, nw);
        }
    }
}

void solve(){
    int cnt = 0;
    for(int i = 0; i < h; i++){
        for(int j = 0; j < w; j++){
            if(field[i][j] == 0) continue;
            field[i][j] = 0;
            dfs(i,j);
            cnt++;
        }
    }

    cout << cnt << endl;
}

int main(){
    while(cin >> w >> h){
        if(h == 0 || w == 0) break;
        rep(i,h)rep(j,w) cin >> field[i][j];
        solve();
    }
}