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
input = sys.stdin.readline
sys.setrecursionlimit(10**7)

out = []
while True:
    W, H = map(int,input().split())
    if W == 0 and H == 0:
        break
    G = [list(map(int,input().split())) for _ in range(H)]
    visited = [[False]*W for _ in range(H)]
    ans = 0
    def dfs(h, w):
        visited[h][w] = True
        for dx in [-1, 0, 1]:
            for dy in [-1, 0, 1]:
                ww, hh = w+dx, h+dy
                if not 0 <= ww < W: continue
                if not 0 <= hh < H: continue
                if G[hh][ww] == 0 or visited[hh][ww]: continue
                dfs(hh, ww)
    for h in range(H):
        for w in range(W):
            if G[h][w] == 0 or visited[h][w]: continue
            ans += 1
            dfs(h, w)
    out.append(ans)
print(*out, sep="\n")

Python: #!/usr/bin/env python3
# -*- coding: utf-8 -*-

import array
import itertools
import sys


class RecursiveDepthFirstSearch(object):

    def __init__(self, width, height, stage):
        self.width = width
        self.height = height
        self.stage = stage

    def search(self, x0, y0):
        if x0 < 0 or self.width <= x0 or y0 < 0 or self.height <= y0:
            pass
        elif self.stage[x0][y0] == 0:
            pass
        else:
            self.stage[x0][y0] = 0
            for dx, dy in itertools.product(range(-1, 2), range(-1, 2)):
                if dx != 0 or dy != 0:
                    self.search(x0 + dx, y0 + dy)


if __name__ == "__main__":
    sys.setrecursionlimit(10000)
    while True:
        w, h = map(int, input().split())
        if w == 0 and h == 0:
            break
        else:
            stage = [array.array("B", x) for x in zip(
                *[list(map(int, input().split())) for y in range(h)])]
            dfs = RecursiveDepthFirstSearch(w, h, stage)
            answer = 0
            for x, y in itertools.product(range(w), range(h)):
                if dfs.stage[x][y] == 1:
                    dfs.search(x, y)
                    answer += 1
            print(answer)

Python: import sys
sys.setrecursionlimit(5000)

c_list = []


def dps(h_i, w_i, h, w, done_list):
    if h_i >= h or w_i >= w or h_i < 0 or w_i < 0:
        return
    if c_list[h_i][w_i] == 1 and done_list[h_i][w_i] == False:
        done_list[h_i][w_i] = True
        for d_h in [-1,0,1]:
            for d_w in [-1, 0, 1]:
                if d_h == 0 and d_w == 0: continue
                n_h, n_w = h_i + d_h, w_i + d_w
                if n_h >= h or n_w >= w or n_h < 0 or n_w < 0: continue

                dps(h_i-1, w_i, h, w, done_list)
                dps(h_i+1, w_i, h, w, done_list)

                dps(h_i, w_i-1, h, w, done_list)
                dps(h_i, w_i+1, h, w, done_list)

                dps(h_i-1, w_i-1, h, w, done_list)
                dps(h_i-1, w_i+1, h, w, done_list)

                dps(h_i+1, w_i-1, h, w, done_list)
                dps(h_i+1, w_i+1, h, w, done_list)

        
def main():
    global c_list
    c_list = []
    w,h = map(int, input().split())
    if w == 0 and h == 0:
        return False

    for i in range(h):
        c_list.append(list(map(int,input().split())))

    done_list = [[False for _ in range(w)] for _i in range(h)]
    cnt = 0
    for h_i in range(h):
        for w_i in range(w):
            if not done_list[h_i][w_i] and c_list[h_i][w_i] == 1:
                dps(h_i, w_i, h, w, done_list)
                cnt += 1
    return cnt

if __name__ == "__main__":
    rl = []
    while True:
        res = main()
        if res is False: break
        else:
            rl.append(res)
    for r in rl:
        print(r)

Python: 
#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)

Python: import sys

sys.setswitchinterval(10**8)


next_s = ((-1, 1), (0, 1), (1, 1),
          (-1, 0), (1, 0),
          (-1, -1), (0, -1), (1, -1))


def DFS(x, y):
    if not (0 <= x < W and 0 <= y < H):
        return
    if not map_[y * W + x]:
        return

    map_[y * W + x] = 0

    for dx, dy in next_s:
        DFS(x + dx, y + dy)


while True:
    W, H = map(int, input().split())
    if W == 0 and H == 0:
        break

    map_ = []
    for h in range(H):
        map_ += list(map(int, input().split()))
    island_num = 0
    while any(map_):
        next_idx = map_.index(1)
        x = next_idx % W
        y = next_idx // W
        DFS(x, y)
        island_num += 1

    print(island_num)