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

dx = [0, 1, 1, 1, 0, -1, -1, -1]
dy = [1, 1, 0, -1, -1, -1, 0, 1]
w = 0
h = 0


def main():
    global w, h

    while True:
        count = 0
        w, h = map(int, input().split())
        if w is 0 and h is 0:
            break
        field = []
        [field.append(list(map(int, input().split()))) for _ in range(h)]

        for y in range(h):
            for x in range(w):
                if field[y][x] == 1:
                    dfs(field, x, y)
                    count += 1

        print(count)


def dfs(field, x, y):
    field[y][x] = 0

    for dx_, dy_ in zip(dx, dy):
        next_x = x + dx_
        next_y = y + dy_
        if next_x < 0 or next_y < 0 or next_x >= w or next_y >= h or field[next_y][next_x] == 0:
            continue
        dfs(field, next_x, next_y)


if __name__ == '__main__':
    sys.setrecursionlimit(10000)
    main()

Python: import sys

sys.setrecursionlimit(1000000)

D = [(1,0), (0,1), (-1,0), (0,-1), (-1,-1),(1,-1),(-1,1),(1,1) ] # 下、右、上、左、斜め

def dfs(x,y):
  # Validation
  if not(0<=x<H and 0<=y<W) : return

  # 探索済みか、探索可能かを確認する
  if f[x][y]!=0 or G[x][y] == 0: return

  # Validation完了、探索範囲内、探索可能、ゴール以外＝＞visitフラグを立てる
  f[x][y]=1
 
  # 次の場所に向かう
  for dx,dy in D:
     nx=x+dx
     ny=y+dy
     dfs(nx,ny)
  return

def main():

    cnt=0
    for i in range(H):
        for j in range(W):
            if f[i][j]==0 and G[i][j]: 
                dfs(i, j)
                cnt+=1
    print(cnt)

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)]
    f=[[0]*W for _ in range(H)]

    main()

Python: import sys
sys.setrecursionlimit(20000)
w,h=list(map(int,input().split()))
def simaserach(i,j):
    if color[i][j]=="w":
        color[i][j]="g"
        if i>=1:
            if sima[i-1][j]==1:
                simaserach(i-1,j)
            if j>=1:
                if sima[i-1][j-1]==1:
                    simaserach(i-1,j-1)
            if j<=w-2:
                if sima[i-1][j+1]==1:
                    simaserach(i-1,j+1)
        if j>=1:
            if sima[i][j-1]==1:
                simaserach(i,j-1)
        if j<=w-2:
            if sima[i][j+1]==1:
                simaserach(i,j+1)
        if i<=h-2:
            if j>=1:
                if sima[i+1][j-1]==1:
                    simaserach(i+1,j-1)
            if sima[i+1][j]==1:
                simaserach(i+1,j)
            if j<=w-2:
                if sima[i+1][j+1]:
                    simaserach(i+1,j+1)

while(w!=0):
    count=0
    color = [["w" for i in range(w)] for j in range(h)]
    sima=[[]for i in range(h)]
    for i in range(h):
        a=list(map(int,input().split()))
        sima[i]=a
    for i in range(h):
        for j in range(w):
            if sima[i][j]==1 and color[i][j]=="w":
                simaserach(i,j)
                count+=1
    print(count)
    w, h = list(map(int, input().split()))

Python: import sys
sys.setrecursionlimit(10**6)
from itertools import product
while True:
  w,h = map(int,input().split())
  if w == h == 0: exit()
  islands = []
  for _ in range(h):
    islands.append(list(map(int,input().split())))

  seen = [ [False]*w for _ in range(h) ]
  def dfs(row,col):
    seen[row][col] = True

    for x,y in product(range(-1,2), repeat=2):
      if x==0 and y==0: continue
      nrow, ncol = row+x, col+y
      if nrow>=h or nrow<0 or ncol>=w or ncol<0: continue
      if seen[nrow][ncol]: continue

      if islands[nrow][ncol] == 1:
        dfs(nrow, ncol)

  res = 0
  for i in range(h):
    for j in range(w):
      if islands[i][j] == 1 and not seen[i][j]:
        dfs(i,j)
        res += 1

  print(res)

Python: import sys
sys.setrecursionlimit(2500)
 
def erase(x, y):
    c[y][x] = '0'
    for dx, dy in ((1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1), (0, -1), (1, -1)):
        nx, ny = x + dx, y + dy
        if 0 <= nx < w and 0 <= ny < h and c[ny][nx] == '1':
            erase(nx, ny)
 
while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    c = [sys.stdin.readline().split() for _ in range(h)]
    ans = 0
    for y in range(h):
        for x in range(w):
            if c[y][x] == '1':
                ans += 1
                erase(x, y)
    print(ans)

Python: import sys
sys.setrecursionlimit(10000)
k = [-1,0,1]
def search(x,y,m):
    if x<0 or x>=len(m[0]) or y<0 or y>=len(m): return
    if m[y][x]==0: return
    m[y][x] = 0
    for i in k:
        for j in k:
            search(x+i,y+j,m)

while True:
    c = 0
    w,h = map(int,input().split())
    if w==0: break
    m = [list(map(int,input().split())) for i in range(h)]
    for i in range(h):
        for j in range(w):
            if m[i][j]==1:
                search(j, i, m)
                c += 1
    print(c)

Python: import sys


def dfs(M, i, j, h, w):
    M[i][j] = 0
    for dy in range(-1, 2):
        for dx in range(-1, 2):
            ny, nx = i+dy, j+dx
            if 0 <= ny < h and 0 <= nx < w and M[ny][nx] == 1:
                dfs(M, ny, nx, h, w)


def search(M, w, h):
    count = 0
    for i in range(h):
        for j in range(w):
            if M[i][j] == 1:
                dfs(M, i, j, h, w)
                count += 1
    return count


if __name__ == "__main__":
    sys.setrecursionlimit(50*50)
    ans = []
    while True:
        w, h = map(int, input().split())
        if w == 0 and h == 0:
            break
        M = [[int(ipt) for ipt in input().split()] for _ in range(h)]
        ans.append(search(M, w, h))

    for a in ans:
        print(a)