Data Structure: Tree

mind the data structure: here comes the tree

Recursively Traverse a Tree

Top-down: node first, like a pre-order
Bottom-up: like post-order

BST: Binary Search Tree

Left sub-tree key <= parent node’s key
Right sub-tree key >= parent node’s key

left sub-tree key <= node key <= right sub-tree key

Validate

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None


class Solution:
    def isValidBST(self, root):
        """
        :type root: TreeNode
        :rtype: bool
        """
        return self.BST(root, -2147483649, 2147483648)

    def BST(self, root, min, max):
        if root == None:
            return True
        if root.val <= min or root.val >= max:
            return False
        else
        return self.BST(root.left, min, root.val ) and self.BST(root.right, root.val, max)

Planted: 2018-03-27 by L Ma;

Dynamic Backlinks to wiki/algorithms/data-structure-tree:

Data Structure: Tree

mind the data structure: here comes the tree

wiki/algorithms/data-structure-tree Links to:

Data Structure

mind the data structure

L Ma (2018). 'Data Structure: Tree', Datumorphism, 03 April. Available at: https://datumorphism.leima.is/wiki/algorithms/data-structure-tree/.