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: from collections import deque


def dfs(G, start):
    S = deque()
    child = deque()
    VL[start[1]][start[0]] = 1
    S.append(start)
    while len(S) > 0:
        node = S.pop()
        for i in range(len(dx)):
            child.clear()
            nx = node[0] + dx[i]
            ny = node[1] + dy[i]

            if nx < 0 or nx >= W or ny < 0 or ny >= H:
                continue
            if G[ny][nx] == 0:
                continue
            if VL[ny][nx] == 1:
                continue

            child.append((nx, ny))

            if len(child) > 0:
                for c in child:
                    VL[c[1]][c[0]] = 1
                    S.append(c)


ok = True
while ok:
    W, H = map(int, input().split())

    if W == 0 and H == 0:
        break

    G = [list(map(int, input().split())) for _ in range(H)]
    VL = [[0 for _ in range(W)] for _ in range(H)]

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

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

    print(res)

Python: import sys
sys.setrecursionlimit(10000)
def f(x,y):
    if 0<=x<w and 0<=y<h and a[y][x]=='1':
        a[y][x]='0'
        for dx,dy in[[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[1,-1],[-1,1],[1,1]]:f(x+dx,y+dy)
while 1:
    w,h=map(int,input().split())
    if w==0:break
    a=[input().split() for _ in[0]*h];b=0
    for i in range(w):
        for j in range(h):
            if a[j][i]=='1':
                b+=1;f(i,j)
    print(b)

Python: import sys
while True:
    sys.setrecursionlimit(10000000)
    w,h=map(int,input().split())
    if w==0 and h==0:
        sys.exit()

    field=[list(map(int,input().split())) for i in range(h)]

    def dfs(x,y):
        if not(0<=x<h) or not(0<=y<w):
            return
        elif field[x][y]==0:
            return
        field[x][y]=0
        for i in range(3):
            for j in range(3):
                dfs(x-1+i,y-1+j)
        return 0
    ans=0
    for i in range(h):
        for j in range(w):
            if field[i][j]==1:
                dfs(i,j)
                ans+=1     
    print(ans)

Python: import sys

sys.setrecursionlimit(2 * 10**6)


def inpl():
    return list(map(int, input().split()))


def solve(mp, w, h):
    def dfs(ny, nx):
        if mp[ny][nx] == 0:
            flag[ny][nx] = -1
            return
        elif visit[ny * w + nx]:
            return
        visit[ny * w + nx] = True

        for dx in [-1, 0, 1]:
            for dy in [-1, 0, 1]:
                if dx == dy == 0:
                    continue
                elif mp[ny + dy][nx + dx] == 0:
                    continue
                flag[ny + dy][nx + dx] = min(flag[ny][nx], flag[ny + dy][nx + dx])
                dfs(ny + dy, nx + dx)

    mp = [[0] + m + [0] for m in mp]
    mp = [[0] * (w + 2)] + mp + [[0] * (w + 2)]
    flag = [[-1] + [i + j * w for i in range(w)] + [-1] for j in range(h)]
    flag = [[-1] * (w + 2)] + flag + [[-1] * (w + 2)]
    visit = [False] * (w + 2) * (h + 2)

    for ny in range(h):
        for nx in range(w):
            dfs(ny + 1, nx + 1)
    # print(flag)

    ret = []
    for f in flag:
        ret += [i for i in f if i != -1]
    return len(set(ret))


ans = []
while True:
    w, h = inpl()
    if w == h == 0:
        break
    tmp = [inpl() for i in range(h)]
    ans.append(solve(tmp, w, h))

for a in ans:
    print(a)

Python: import sys
sys.setrecursionlimit(100000)

def islands ( x, y):
    s[y][x] = '0'
    for dx, dy in ((1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1), (0, -1), (1, -1)):
        xx,yy = x+dx , y+dy
        if 0<=xx<w and 0<=yy<h and s[yy][xx]=='1':
            islands(xx,yy)
            
while True:
    w, h = map(int, input().split())
    count = 0

    if w==0 and h==0:
        break
    
    s = [[i for i in input().split()] for _ in range(h)]


    for i in range (w):
        for j in range(h):
            if s[j][i] == '1':
                islands( i, j)
                count += 1

    print(count)

Python: # https://onlinejudge.u-aizu.ac.jp/problems/1160

A = []
w = 0
h = 0


def walk(i, j):
    global A
    stack = [(i, j)]
    while True:
        i, j = stack.pop()
        A[i][j] = 0
        for ii in range(i-1, i+2):
            for jj in range(j-1, j+2):
                if ii < 0 or h <= ii:
                    continue
                if jj < 0 or w <= jj:
                    continue
                if A[ii][jj] == 0:
                    continue
                else:
                    stack.append((ii, jj))

        if len(stack) == 0:
            break


if __name__ == "__main__":
    while True:
        w, h = map(int, input().split())
        if w == 0 and h == 0:
            break

        A = []
        for i in range(h):
            row = list(map(int, input().split()))
            A.append(row)

        cnt = 0
        for i in range(h):
            for j in range(w):
                if A[i][j] == 1:
                    cnt += 1
                    walk(i, j)

        print(cnt)

Python: # -*- coding: utf-8 -*-
def dfs(x,y):
    c[x][y] = 0
    for dx in [-1,0,1]:
        for dy in [-1,0,1]:
            nx = x + dx
            ny = y + dy
            if 0 <= nx < h and 0 <= ny < w and c[nx][ny] == 1:
                dfs(nx, ny)

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

    print(count)