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(1000000)


def dfs(map, reached, pos):
    global dx, dy
    x, y = pos

    if reached[x][y] == 1 or map[x][y] == '0':
        return 0

    reached[x][y] = 1
    for dxi, dyi in zip(dx, dy):
        if not reached[x + dxi][y + dyi]:
            dfs(map, reached, (x + dxi, y + dyi))

    return int(map[x][y])


def island(map):
    w = len(map)
    h = len(map[0])
    reached = [[0] * h for _ in range(w)]

    ans = 0
    for x in range(w):
        for y in range(h):
            if reached[x][y] == 1 or map[x][y] == '0':
                continue
            ans += dfs(map, reached, (x, y))

    return ans


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

while True:
    w, h = map(int, input().split())

    if (0, 0) == (w, h):
        break

    mapp = ['0' * (w + 2)]
    for _ in range(h):
        mapp.append('0%s0' % input().replace(' ', ''))
    mapp.append('0' * (w + 2))
    print(island(mapp))

Python: import sys

sys.setrecursionlimit(10000)

def dfs(pos):
    x = pos[0]
    y = pos[1]
    C[y][x] = -1
    
    for x_d, y_d in [[1,0],[1,1],[0,1],[1,-1],[-1,1],[-1,0],[-1,-1],[0,-1]]:        
        x_new = x+x_d
        y_new = y+y_d

        if not 0<=x_new<=w-1:
            continue

        if not 0<=y_new<=h-1:
            continue

        if C[y_new][x_new]!=1:
            continue

        dfs([x_new, y_new])

while True:
    w, h = map(int, input().split())
    if w==h==0:
        break
    
    C = [list(map(int, input().split())) for _ in range(h)]
    
    counter = 0
    for w_i in range(w):
        for h_i in range(h):
            
            if C[h_i][w_i]==1:
                counter += 1
                dfs([w_i,h_i])
    
    print(counter)

Python: import sys
def f(n):
  if n%100==0:
    print>>sys.stderr, n
  f(n+1)
f(1)

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: import sys
sys.setrecursionlimit(10000)

def main():
    ans=[]
    while True:
        w,h=map(int,input().split())
        if w==0 and h==0:
            break
        dis=[-1,0,1]
        c=[[0]*(w+2)]
        for i in range(h):
            c.append([0]+list(map(int,input().split()))+[0])
        c.append([0]*(w+2))
        chk=[[0]*(w+2) for _ in range(h+2)]

        def dfs(x,y):
            chk[x][y]=1
            if x<=0 or y<=0 or x>=h+1 or y>=w+1 or c[x][y]==0:
                return
            for dx in dis:
                for dy in dis:
                    if chk[x+dx][y+dy]==0 and c[x+dx][y+dy]==1:
                        dfs(x+dx,y+dy)
            return

        cnt=0
        for i in range(1,h+1):
            for j in range(1,w+1):
                if chk[i][j]==0:
                    chk[i][j]=1
                    if c[i][j]==1:
                        dfs(i,j)
                        cnt+=1
        ans.append(cnt)
    for i in ans:
        print(i)

if __name__ == '__main__':
    main()

Python: from sys import stdin
from sys import setrecursionlimit
setrecursionlimit(10**9)

def dfs(y,x):
    for dy,dx in (-1,0),(1,0),(0,-1),(0,1),(-1,-1),(-1,1),(1,-1),(1,1):
        ny,nx=y+dy,x+dx
        if 0<=ny<h and 0<=nx<w:
            if grid[ny][nx]==1:
                grid[ny][nx]=0
                dfs(ny,nx)

while True:
    readline=stdin.readline
    w,h=map(int,readline().split())
    if w==0 and h==0:
        break
    grid=[list(map(int,readline().split())) for _ in range(h)]

    cnt=0
    for y in range(h):
        for x in range(w):
            if grid[y][x]==1:
                dfs(y,x)
                cnt+=1

    print(cnt)

Python: import sys
sys.setrecursionlimit(10000)
def dfs(x,y):
    for i in range(-1,2):
        if 0<=x+i<a[1]:
            for j in range(-1,2):
                if 0<=y+j<a[0]:
                    if G[x+i][y+j]==1:
                        G[x+i][y+j] = 0
                        dfs(x+i,y+j)
while  True:
    a = list(map(int, input().split()))
    if a[0] == 0:
        break
    G = []
    cnt = 0
    for i in range(a[1]):
        G.append(list(map(int, input().split())))
    for i in range(a[1]):
        for j in range(a[0]):
            if G[i][j] == 1:
                cnt += 1
                dfs(i,j)
    print(cnt)