Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

Python: import sys
sys.setrecursionlimit(10000)

def main():
    while 1:
        W, H = map(int, input().split())
        if W == 0 and H == 0:
            break
        C = [list(map(int, input().split())) for _ in range(H)]

        def dfs(h, w):
            C[h][w] = 0

            for dh in range(-1, 2):
                for dw in range(-1, 2):
                    nh = h + dh
                    nw = w + dw
                    if nh < 0 or nh >= H or nw < 0 or nw >= W:
                        continue
                    if C[nh][nw] == 0:
                        continue
                    dfs(nh, nw)

        count = 0
        for h in range(H):
            for w in range(W):
                if C[h][w] == 0:
                    continue
                dfs(h, w)
                count += 1
        print(count)


if __name__ == "__main__":
    main()

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

def dfs(s,Map,H,W,c):
    dxdy = [(1,0),(-1,0),(0,1),(0,-1),(1,1),(-1,-1),(-1,1),(1,-1)]
    for i in range(8):
        Map[s[0]][s[1]] = c
        nextPos = (s[0]+dxdy[i][0],s[1]+dxdy[i][1])
        if nextPos[0] >= 0 and nextPos[1] >= 0 and nextPos[0] < H and nextPos[1] < W:
            if Map[nextPos[0]][nextPos[1]] == 1:
                dfs(nextPos,Map,H,W,c)

while True:
    W,H = map(int,input().split(" "))
    if W == 0 and H == 0:
        break
    Map = [list(map(int,input().split())) for i in range(0,H)]
    c = 1
    for i in range(H):
        for j in range(W):
            if Map[i][j] == 1:
                c += 1
                dfs((i,j),Map,H,W,c)
    print(c-1)

Python: def dfs(w,h,W,H,ID,islands,islandsID):
    if islands[h][w]==1 and islandsID[h][w]!=0:
        for i in range(-1,2):
            for j in range(-1,2):
                dw=w+i
                dh=h+j
                if dw>=0 and dw<W and dh>=0 and dh<H:
                    if islands[dh][dw]==1:
                        islandsID[dh][dw]=islandsID[h][w]
    if islands[h][w]==1 and islandsID[h][w]==0:
        for i in range(-1,2):
            for j in range(-1,2):
                dw=w+i
                dh=h+j
                if dw>=0 and dw<W and dh>=0 and dh<H:
                    if islands[dh][dw]==1:
                        islandsID[dh][dw]=ID
        ID+=1
    return ID

while True:
    islands=[]
    islandsID=[]
    ID=1
    W,H=map(int,input().split())
    if W==0:
        break
    for i in range(H):
        islandsID.append([0 for j in range(W)])
    for _ in range(H):
        islands.append(list(map(int,input().split())))
    for h in range(H):
        for w in range(W):
            ID=dfs(w,h,W,H,ID,islands,islandsID)
    print(ID-1)

Python: import itertools
import sys
sys.setrecursionlimit(5000)


class TestInput:
    @classmethod
    def input(self):
        TestInput.current += 1
        return TestInput.data.splitlines()[TestInput.current]
    current = -1
    data = '''\
2 2
0 1
1 0
5 4
1 0 1 0 0
1 0 0 0 0
1 0 1 0 1
1 0 0 1 0
0 0
'''


def read_input():
    # return TestInput.input()
    return input()


class IslandMap:
    moves = list(itertools.product([-1, 0, 1], [-1, 0, 1]))

    def __init__(self, w, h, c):
        self.w = w
        self.h = h
        self.c = c

    def dfs(self, p):
        self.c[p[0]][p[1]] = 0
        for m in IslandMap.moves:
            n = (p[0] + m[0], p[1] + m[1])
            if 0 <= n[0] < self.h and 0 <= n[1] < self.w:
                if self.c[n[0]][n[1]] == 1:
                    self.dfs(n)

    def solve(self):
        region = 0
        lattice = itertools.product(range(self.h), range(self.w))
        for p in lattice:
            if self.c[p[0]][p[1]] == 1:
                self.dfs(p)
                region += 1
        return region


while True:
    w, h = map(int, read_input().split())
    if w == 0 or h == 0:
        break
    c = [list(map(int, read_input().split())) for i in range(h)]
    island = IslandMap(w, h, c)
    print(island.solve())

Python: # -*- coding: utf-8 -*-
#150 島は幾つある？
h,w=1,1

count=0
anser=0

def search(x,y):
    #マップの外側か壁の場合は何もしない
    #print(x,y)

    global count
    count+=1
    if x<0 or x>w-1 or y<0 or y>h-1 or map_data[y][x]==0:
 
        return
        
    
    #以前に到達していたら何もしない
    if reached[y][x] ==0:
         return

    reached[y][x]=0
    
    #print("aa")



    search(x+1,y)#右
    search(x-1,y)#左
    search(x,y+1)#上
    search(x,y-1)#下
    search(x-1,y-1)
    search(x-1,y+1)
    search(x+1,y-1)
    search(x+1,y+1)



while h!=0 and w!=0: 
    anser=0
    count=1
    #グラフの入力方法------

    w,h=map(int ,raw_input().split())
    if h==0 and w==0:
        break

    map_data = [[0]*w for _ in range(h)]
    reached = [[1]*w for _ in range(h)]

    for i in range(h):
        ct = raw_input().split()
       
        for j in range(w):
            map_data[i][j] = int(ct[j])
            reached [i][j]=int(ct[j])
            if ct[j]==1:
                sx=j
                sy=i

    t=0
    a=0
    while a<=h:
       if 1 in reached[t%h]:         
            search(reached[t%h].index(1),t%h)
            anser+=1
            #print("count",count)
            count=1
            a=0
       elif count==h:
                break
       t+=1
       a+=1

    print(anser)

    #------