Problem Link:
https://oj.leetcode.com/problems/validate-binary-search-tree/
We inorder-traverse the tree, and for each node we check if current_node.val > prev_node.val. The code is as follows.
...
In this problem, your job to write a function to check whether a input string is a valid IPv4 address or IPv6 address or neither.
IPv4 addresses are canonically represented in dot-decimal nota...
Validate Binary Search Tree
Given a binary tree, determine if it is a valid binary search tree (BST).
Assume a BST is defined as follows:
The left subtree of a node contains only nodes with keys le...
Given a binary tree, determine if it is a valid binary search tree (BST).
Assume a BST is defined as follows:
The left subtree of a node contains only nodes with keys less than the node's...
Given a binary tree, determine if it is a valid binary search tree (BST).
Assume a BST is defined as follows:
The left subtree of a node contains only nodes with keys less than the node's...
using system;
using system.text.regularexpressions;
namespace consoleapp375
{
class program
{
static void main(string[] args)
{
regularexpressiondemo();
...