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>
#define debug(x) cerr << #x << ": " << x << '\n';
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = (int)1e9;

int w, h;
int c[51][51];
int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};

void dfs(int y, int x){
	c[y][x] = 0;
	for(int i = 0; i < 8; i++){
		int ny = y + dy[i], nx = x + dx[i];
		if(0<=ny and ny<h and 0<=nx and nx<w and c[ny][nx]==1){
			dfs(ny, nx);
		}
	}
}

int solve(){
	int res = 0;
	for(int i = 0; i < h; i++){
		for(int j = 0; j < w; j++){
			if(c[i][j] == 1){
				dfs(i, j);
				res++;
			}
		}
	}

	return res;
}

int main(void){
	while(scanf("%d%d", &w, &h) != EOF){
		if(w == 0 and h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &(c[i][j]));
			}
		}
		printf("%d\n", solve());
	}

	return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
 
using namespace std;
const int dx[] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy[] = {-1, 0, 1, -1, 1, -1, 0, 1};
 
int main(void) {
    int w,h;
    while(cin >> w >> h && w && h) {
        vector< vector<int> > data(h+2,vector<int>(w+2,0));
        for (int i = 1; i <= h; ++i) {
            for (int j = 1; j <= w; ++j) {
                cin >> data[i][j];
            }
        }
 
        int nx,ny;
        int count = 0;
        for (int i = 1; i <= h; ++i) {
            for (int j = 1; j <= w; ++j) {
                if (data[i][j] == 1) {
                    nx = j;
                    ny = i;
                    data[i][j] = 0;
                    queue<int> fx,fy;
                    fx.push(nx);
                    fy.push(ny);
                    ++count;
 
                    while (!fx.empty()) {
                        nx = fx.front();
                        ny = fy.front();
                        fx.pop();
                        fy.pop();
                        for (int d = 0; d < 8; ++d) {
                            if (data[ny+dy[d]][nx+dx[d]] == 1) {
                                fx.push(nx+dx[d]);
                                fy.push(ny+dy[d]);
                                data[ny+dy[d]][nx+dx[d]] = 0;
                            }
                        }
                    }
                }
            }
        }
        cout << count << endl;
    }
    return 0;
}

C++: #include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
#include<cstdio>
#include<cmath>
#define pb(in,tmp) in.push_back(tmp)
#define loop(i,a,b) for(int i=a;i<b;i++)
#define rep(i,b) loop(i,0,b)
#define all(in) in.begin(),in.end()
using namespace std;
void isl(int in[50][50],int x,int y){
in[x][y]=0;
loop(i,-1,2){
loop(j,-1,2){
if(x-i>=0&&x-i<50&&y-j>=0&&y-j<50&&in[x-i][y-j])isl(in,x-i,y-j);
}
}
}
int main(){
int n,m;
while(cin>>n>>m,n||m){
int in[50][50]={0};
int co=0;
rep(i,m)
rep(j,n)
cin>>in[i][j];

rep(i,m){
rep(j,n){
if(in[i][j]){co++;isl(in,i,j);}
}
}
cout<<co<<endl;
}
}

C++: #include <iostream>
#include <vector>
#include <list>
#include <set>
#include <string>
#include <cmath>
#include <algorithm>
#include <map>

using namespace std;
using ll=long long;
using vi=vector<int>;
using vll=vector<ll>;
using pii=pair<int,int>;
using vs=vector<string>;
using vvi=vector<vi>;
using vpii=vector<pii>;
using si=set<int>;

#define REP(i,a) for(int i=0;i<a;i++)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define rREP(i,a) for(int i=(a)-1;i>=0;i--)
#define rFOR(i,a,b) for(int i=(a)-1;i>=(b);i--)
#define out(S) cout<<(S)<<endl;
#define beginend(v) (v).begin(),(v).end()
#define IfOut(condition,text) if(condition){out(text);return 0;}
#define IfOutElse(condition,if_text,else_text) if(condition){out(if_text);return 0;}else{out(else_text);return 0;}
#define mod(s) ((s)%(ll)(1e9+7))
ll modpow(ll i, ll j) { ll tmp = 1; while (j) { if (j % 2)tmp = mod(tmp*i); i = mod(i*i); j /= 2; }return tmp; }
#define divmod(a,b) (mod(a*modpow((ll)b,(ll)(1e9+5))))
#define pb(i) push_back(i)
#define fst first
#define snd second
#define Foreach(item,collection) for(auto item:collection)
#define INF (int)1e10
#define removeAll(vec,deleg) auto itr=remove_if(beginend(vec),deleg);vec.erase(itr,vec.end());
void removeAt(string& s, int index) { s.erase(index, 1); }
template<typename T> void removeAt(vector<T>& v, int index) { v.erase(v.begin() + index); }
ll manhattanDistance(ll x1, ll y1, ll x2, ll y2) { return (abs(x2 - x1) + abs(y2 - y1)); }
vector<ll> sieveOfEratosthenes(int max) {ll prime;double sqrtmax = sqrt(max);vector<ll> primeVec, searchVec;FOR(i, 2, max + 1) searchVec.push_back(i);do{prime = searchVec[0];primeVec.push_back(prime);auto itr = remove_if(beginend(searchVec), [=](ll x)->bool {return x%prime == 0; });searchVec.erase(itr, searchVec.end());} while (prime < sqrtmax);primeVec.reserve(primeVec.size() + searchVec.size());primeVec.insert(primeVec.end(), beginend(searchVec));return primeVec;}
ll sum(vi v) {ll sum=0;Foreach(i,v){sum+=i;}return sum;}
#define ShowAll(v) Foreach(i,v) out(i);
bool isInnerIndex(ll x,ll y,ll mx,ll my){ return (x>=0&&x<mx&&y>=0&&y<my); }

int x,y;
vvi box;
int dx[]{0,1,0,-1,1,1,-1,-1};
int dy[]{1,0,-1,0,-1,1,-1,1};
ll s=0;
void dfs(int px,int py){
    REP(i,8){
        int nx=px+dx[i];
        int ny=py+dy[i];
        if(isInnerIndex(nx,ny,x,y)&&box[ny][nx]==1){
            dfs(nx,ny);
        }
    }
    return;
}

int main(){
    vi ans;
    while (cin>>x>>y,(x||y))
    {
        box.clear();
        box.resize(y);
        REP(i,y) REP(n,x) {
            int c;
            cin>>c;
            box[i].pb(c);
        }
        ll s=0;
        REP(i,y)REP(n,x){
            if(box[i][n]==1) {dfs(n,i);s++;}
        }
        ans.pb(s);
    }
    
    ShowAll(ans);
    return 0;
}

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

using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define vec vector

int dx[8] = {0, 0, 1, 1, 1,-1,-1,-1};
int dy[8] = {1,-1,-1, 0, 1,-1, 0, 1};

int dp[55][55];
int c[55][55];

int check(int x, int y)
{
	if (dp[x][y]) return 0;
	if (c[x][y] == 0) return 0;
	dp[x][y] = 1;
	
	rep(i, 8) {
		int xx = x + dx[i];
		int yy = y + dy[i];
		int take = check(xx, yy);
	}
	return 1;
}

int main(void)
{
	while(1) {
		int w, h;
		cin >> w >> h;
		if (w == 0) break;
		rep(i, 50) rep(j, 50) c[i + 1][j + 1] = 0;
		rep(i, h) rep (j, w) cin >> c[i + 1][j + 1];
		rep(i, 50) rep(j, 50) dp[i][j] = 0;
		rep(i, 55) {
			dp[0][i] = 1;
			dp[i][0] = 1;
			dp[h + 1][i] = 1;
			dp[i][w + 1] = 1;
		}

		int ans = 0;
		rep(i, h) rep(j, w) if (c[i + 1][j + 1]) ans += check(i + 1, j + 1);
		cout << ans << endl;
	}
	return 0;
}