【数据结构与算法】【LeetCode】【二叉树】104.二叉树的最大深度

from queue import Queue

class TreeNode:
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None
def create_tree(list_tree):
    if  not list_tree:
        return []
    new_queue= Queue()
    root = TreeNode(list_tree[0])
    new_queue.put(root) # 先入队一个结点
    count = 1
    while not new_queue.empty() and count<len(list_tree):
        dequeue = new_queue.get() # 出队
        if not dequeue.left and  not dequeue.right:
            if count<len(list_tree) and list_tree[count]:
                dequeue.left=TreeNode(list_tree[count])
            count= count+1
            if count<len(list_tree) and list_tree[count]:
                dequeue.right=TreeNode(list_tree[count])
            count= count+1

            if dequeue.left:
                new_queue.put(dequeue.left)
            if dequeue.right:
                new_queue.put(dequeue.right)
    return root

class Solution:
    def maxDepth(self, root: TreeNode) -> int:
        if root is None:
            return 0
        left=1+self.maxDepth(root.left)
        right=1+self.maxDepth(root.right)
        
        if left<right:
            return right
        else:
            return left

root =  [1,2,3,4,None,None,5]
root_tree=create_tree(root)
a=Solution()
result =a.maxDepth(root_tree)
result

from collections import deque
class Solution:
    def maxDepth(self, root: TreeNode):
        if root is None:
            return 0
        new_deque=deque()
        new_deque.append(root)
        count=0
        while len(new_deque):
            size=len(new_deque)
            while size>0:
                cur=new_deque.popleft()
                
                if cur.left:
                    new_deque.append(cur.left)
                if cur.right:
                    new_deque.append(cur.right)
                size=size-1
            count=count+1
        return count
root =  [1,2,3,4,None,None,5]
root_tree=create_tree(root)
a=Solution()
result =a.maxDepth(root_tree)
result