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: 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
from collections import deque
input = sys.stdin.readline
def RD(): return input().rstrip()
def F(): return float(input().rstrip())
def I(): return int(input().rstrip())
def MI(): return map(int, input().split())
def MF(): return map(float,input().split())
def LI(): return list(map(int, input().split()))
def LF(): return list(map(float,input().split()))
def Init(H, W, num): return [[num for i in range(W)] for j in range(H)]


def main():
    move = [[i, j] for i in range(-1,2) for j in range(-1,2) if not(i==j and i == 0)]
    try:
        while True:
            w, h = MI()
            if w == h and h == 0:
                sys.exit()
            d = Init(h, w, True)
            mylist = [LI() for i in range(h)]
            result = 0
            for i in range(h):
                for j in range(w):
                    if d[i][j] and mylist[i][j] == 1:
                        result+=1
                        dq = deque()
                        dq.append([i, j])
                        while dq:
                            x, y = dq.pop()
                            for x2, y2 in move:
                                x2 += x
                                y2 += y
                                if x2 >= 0 and x2 < h and y2 >= 0 and y2 < w:
                                    if mylist[x2][y2] == 1 and d[x2][y2]:
                                        dq.append([x2,y2])
                                        d[x2][y2] = False
                                    elif d[x2][y2]:
                                        d[x2][y2] = False
            print(result)
    except:
        sys.exit()
    
    
    
if __name__ == "__main__":
    main()

Python: import sys
sys.setrecursionlimit(10**6)

def erase(w, h, 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 -1 and 0 <= ny <= h - 1:
            if c[ny][nx] == '1':
                erase(w, h, nx, ny)

while True:
    w, h = map(int, input().split())
    if w == h == 0:
        break
    c = [[i for i in input().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(w, h, x, y)
    print(ans)

Python: import queue

def proceess(start_x,start_y):
    #insland = []
    #insland.append([start_x,start_y])
    new_island = queue.Queue()
    map[start_x][start_y] = 0
    new_island.put([start_x,start_y])
    while True:
        ob = new_island.get()
        x = ob[0]
        y = ob[1]
        print("x : " + str(x) + ", y : " + str(y))

        for i in [-1,0,1]:
            for j in [-1,0,1]:
                nx = x + i
                ny = y + j

                if nx >= 0 and ny >= 0 and nx < w and ny < h:
                    print(map[nx][ny])
                    if map[nx][ny] == 1:
                        #insland.append([nx,ny])
                        print("nx : " + str(nx) + ", ny : " + str(ny))
                        new_island.put([nx,ny])
                        map[nx][ny] = 0

        if new_island.empty():
            break

while True:
    map = []

    tmp = input().split(" ")
    w = int(tmp[0])
    h = int(tmp[1])

    if w == 1 and h == 1:
        break


    for j in range(h):
        nova = []
        arm = input()
        for k in arm.split(" "):
            #k.rstrip('\n')
            nova.append(int(k))
        map.append(nova)

    print(map)

    count = 0
    for i in range(w):
        for j in range(h):
            if map[i][j] == 1:
                print("i : " + str(i) + ", j : " + str(j))
                proceess(i,j)
                count += 1

    print(count)

Python: for i in range(10**6):
    W,H=map(int,input().split())
    if H==0 and W==0:
        exit()
    L=[]
    l=[0 for j in range(W+2)]
    L.append(l)
    for h in range(H):
        a=list(map(int,input().split()))
        a=[0]+a+[0]
        L.append(a)
    L.append(l)
    
    P=[[-1 for w in range(W+2)]for h in range(H+2)]
    for h in range(1,H+1):
        for w in range(1,W+1):
            P[h][w]=(h-1)*W+(w-1)
    Size=[[0 for w in range(W+2)]for h in range(H+2)]
    #print(P)
    def find(a):
        x=a%W+1
        y=a//W+1
        if P[y][x]==a:
            return a
        else:
            return find(P[y][x])
    def union(b,c):
        B=find(b)
        C=find(c)
        if B!=C:
            P[C//W+1][C%W+1]=P[B//W+1][B%W+1]
    for h in range(1,H+1):
        for w in range(1,W+1):
            if L[h][w]==1:
                if L[h-1][w-1]==1:
                    union(P[h][w],P[h-1][w-1])
                if L[h-1][w]==1:
                    union(P[h][w],P[h-1][w])
                if L[h][w-1]==1:
                    union(P[h][w],P[h][w-1])
                if L[h-1][w+1]==1:
                    union(P[h][w],P[h-1][w+1])
                if L[h+1][w-1]==1:
                    union(P[h][w],P[h+1][w-1])
                
    cnt=0
    for h in range(1,H+1):
        for w in range(1,W+1):
            P[h][w]=find(P[h][w])
            if L[h][w]==1 and P[h][w]==(h-1)*W+(w-1):
                cnt+=1
    #print(L)
    #print(P)
    print(cnt)