[leetcode 75-19] Number of islands

https://leetcode.com/problems/number-of-islands

Number of Islands - LeetCode

class Solution(object):
    def numIslands(self, grid):
        cnt=0
        dx =[1,-1,0,0]
        dy =[0,0,1,-1]
        def bfs(x,y,grid):
            queue = deque()
            queue.append((x,y))
            grid[x][y] = 0
            while queue:
                x,y = queue.popleft()
                for i in range(4):
                    nx = x+dx[i]
                    ny = y+dy[i]
                    if 0<= nx < len(grid) and 0 <= ny < len(grid[0]):
                        if grid[nx][ny] == "1":                
                            grid[nx][ny] = 0
                            queue.append((nx,ny))

        for i in range(len(grid)):
            for j in range(len(grid[0])):
                if grid[i][j] == "1":
                    bfs(i,j,grid)
                    cnt+=1

        return cnt