501. Find Mode in Binary Search Tree(字典的一些操作)
发布时间:2020-12-14 04:19:19 所属栏目:大数据 来源:网络整理
导读:Given a binary search tree (BST) with duplicates,find all the mode(s) (the most frequently occurred element) in the given BST. Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than or equal
Given a binary search tree (BST) with duplicates,find all the mode(s) (the most frequently occurred element) in the given BST. Assume a BST is defined as follows:
For example: 1 2 / 2 return [2]. Note: If a tree has more than one mode,you can return them in any order. Follow up: Could you do that without using any extra space? (Assume that the implicit stack space incurred due to recursion does not count). # Definition for a binary tree node. class TreeNode: def __init__(self,x): self.val = x self.left = None self.right = None class Solution: def findMode(self,root): """ :type root: TreeNode :rtype: List[int] """ if root is None: return [] dic = {} def inorder(root): if root.left: inorder(root.left) if root.val not in dic: dic[root.val] = 1 else: dic[root.val] += 1 if root.right: inorder(root.right) inorder(root) # print(dic) m = max(dic.values()) # print(m) res = [] for key,value in dic.items(): # print(key,value) if value==m: res.append(key) return res (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |