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++: #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(ll i = 0; i < (n); ++i)
#define FOR(i, m, n) for(ll i = m; i < (n); i++)
#define all(x) (x).begin(),(x).end()
using namespace std;
typedef long long ll;
using vi = vector<int>;
using vii = vector<vi>;
using pii = pair<int, int>; 
using vl = vector<ll>;
using vll = vector<vl>;
using pll = pair<ll, ll>;

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

int w, h;
vector<vector<bool>> seen;
vii field;

void dfs(int r, int c){
    seen[r][c] = true;
    rep(i, 8){
        int nr = r + dy[i];
        int nc = c + dx[i];

        if(nr < 0 || nc < 0 || nr >= h || nc >= w) continue;
        if(field[nr][nc] == 0) continue;
        if(seen[nr][nc]) continue;
        
        dfs(nr, nc);
    }
}

int main() {
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0) return 0;
        field.assign(h, vi(w));
        rep(i, h){
            rep(j, w){
                cin >> field[i][j];
            }
        }
        
        int cnt = 0;
        seen.assign(h, vector<bool>(w, false));
        rep(i, h){
            rep(j, w){
                if(seen[i][j]) continue;
                if(field[i][j] == 0) continue;
                dfs(i, j);
                cnt++;
            }
        }

        cout << cnt << endl;
    }
}

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

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

void dfs(int y,int x,vector<vector<int> >&m){
    m[y][x]=0;
    for(int i=0;i<8;i++){
        int nexty=y+dy[i];
        int nextx=x+dx[i];
        if(nexty<0||nexty>m.size()-1||nextx<0||nextx>m[0].size()-1)continue;
        if(m[nexty][nextx]==1)dfs(nexty,nextx,m);
    }
}


int main(void){
    int h,w;
    int ans;
    vector<vector<int> >m;
    while(true){
        cin>>w>>h;
        if(h==0)break;
        ans=0;
        m=vector<vector<int> >(h,vector<int>(w));
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                cin>>m[i][j];
            }
        }
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                if(m[i][j]==1){dfs(i,j,m);ans++;}
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}

C++: #include <iostream>

using namespace std;

#define PIAR pair<int, int>
int field[52][52];
int dx[] = { -1,  0, 1, 0, -1,  1, 1, -1};
int dy[] = {0 , -1, 0, 1, -1, -1, 1,  1};

void rec(int x, int y) {
	field[x][y] = 0;
	for (int i = 0; i < 8; i++) {
		int nextX = x + dx[i];
		int nextY = y + dy[i];
		if (field[nextX][nextY] == 1) rec(nextX, nextY);
	}
}

int main() {
	int w, h;
	while (cin >> w >> h, w != 0 && h != 0) {
		for (int i = 0; i < 52; i++) {
			for (int j = 0; j < 52; j++) {
				field[i][j] = 0;
			}
		}

		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				cin >> field[i][j];
			}
		}

		int island = 0;
		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				//??¶?????¢???
				if (field[i][j] == 1) {
					rec(i, j);
					island++;
				}
			}
		}
		cout << island << endl;
	}
}

C++: #include <bits/stdc++.h>

void explore(const int i, const int j, const int w, const int h, const std::array<std::array<int, 50>, 50>& state, std::array<std::array<bool, 50>, 50>& visited)
{
    for (int a = -1; a < 2; a++) {
        for (int b = -1; b < 2; b++) {
            if (0 <= i + a && i + a < h && 0 <= j + b && j + b < w && (a != 0 || b != 0) && !visited.at(i + a).at(j + b) && state.at(i + a).at(j + b) == 1) {
                visited.at(i + a).at(j + b) = true;
                explore(i + a, j + b, w, h, state, visited);
            }
        }
    }
}

int main()
{
    while (true) {
        int w, h;
        std::cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }
        int max_land_id = 0;
        std::array<std::array<int, 50>, 50> state;
        std::array<std::array<bool, 50>, 50> visited;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                std::cin >> state.at(i).at(j);
                visited.at(i).at(j) = false;
            }
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (state.at(i).at(j) == 1 && !visited.at(i).at(j)) {
                    visited.at(i).at(j) = true;
                    explore(i, j, w, h, state, visited);
                    ++max_land_id;
                }
            }
        }
        std::cout << max_land_id << std::endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;
int a[52][52];
int sima(int i,int j,int k){
	if(a[i-1][j-1] == 1){
		a[i-1][j-1] = k;
		sima(i-1,j-1,k);
	}
	if(a[i-1][j] == 1){
		a[i-1][j] = k;
		sima(i-1,j,k);
	}
	if(a[i-1][j+1] == 1){
		a[i-1][j+1] = k;
		sima(i-1,j+1,k);
	}
	if(a[i][j-1] == 1){
		a[i][j-1] = k;
		sima(i,j-1,k);
	}
	if(a[i][j+1] == 1){
		a[i][j+1] = k;
		sima(i,j+1,k);
	}
	if(a[i+1][j-1] == 1){
		a[i+1][j-1] = k;
		sima(i+1,j-1,k);
	}
	if(a[i+1][j] == 1){
		a[i+1][j] = k;
		sima(i+1,j,k);
	}
	if(a[i+1][j+1] == 1){
		a[i+1][j+1] = k;
		sima(i+1,j+1,k);
	}
}

int main() {
	int w,h,k;
	while(1){
		for(int i = 0;i < 52;i++){
			for(int j = 0;j < 52;j++){
				a[i][j] = 0;
			}
		}
		cin >> w >> h;
		if(w == 0)break;
		for(int i = 1;i <= h;i++){
			for(int j = 1;j <= w;j++){
				cin >> a[i][j];
			}
		}
		k = 2;
		for(int i = 1;i <= h;i++){
			for(int j = 1;j <= w;j++){
				if(a[i][j] == 1){
					sima(i,j,k);
					k++;
				}
			}
		}
		cout << k-2 <<endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int dx[]={-1,0,1,-1,1,-1,0,1};
int dy[]={-1,-1,-1,0,0,1,1,1};

    int w,h;
void dfs(int i,int j,vector<vector<int>>& x){
        x[i][j]=0;
        for(int r=0;r<8;r++)
            if(0<=i+dx[r] && i+dx[r]<h && 0<=j+dy[r] && j+dy[r]<w && x[i+dx[r]][j+dy[r]])
                dfs(i+dx[r],j+dy[r],x);



}
int main(){
    while(cin>>w>>h,w){
        vector<vector<int>> x(h,vector<int>(w,0));
        for(int i=0;i<h;i++)
            for(int j=0;j<w;j++)
                cin>>x[i][j];
        int cnt=0;
        for(int i=0;i<h;i++)
            for(int j=0;j<w;j++){
                if(x[i][j]){
                    cnt++;
                    dfs(i,j,x);


                }




            }
        cout<<cnt<<endl;



    }


    return 0;
}