Serialize and deserialize a binary tree
Serialization is to store a tree in an array so that it can be later restored and deserialization is reading […]
1718. Construct the Lexicographically Largest Valid Sequence
Given an integer n, find a sequence that satisfies all of the following: The integer 1 occurs once in the sequence. Each integer
Lowest Common Ancestor in a BST
Given a Binary Search Tree (with all values unique) and two nodes n1 and n2 (n1 != n2). You may assume that both nodes exist
2698. Find the Punishment Number of an Integer
Given a positive integer n, return the punishment number of n. The punishment number of n is defined as the sum of the squares of all integers i such that: 1
1352. Product of the Last K Numbers
Design an algorithm that accepts a stream of integers and retrieves the product of the last k integers of the stream. Implement
Fixing Two nodes of a BST
Given the root of a Binary search tree(BST), where exactly two nodes were swapped by mistake. Your task is to fix (or correct) the
3066. Minimum Operations to Exceed Threshold Value II
You are given a 0-indexed integer array nums, and an integer k. In one operation, you will: Take the two smallest integers x and y in nums. Remove x and y from nums. Add min(x,
Pair Sum in BST
Given a Binary Search Tree(BST) and a target. Check whether there’s a pair of Nodes in the BST with value summing
2342. Max Sum of a Pair With Equal Sum of Digits
You are given a 0-indexed array nums consisting of positive integers. You can choose two indices i and j, such that i != j, and the sum of digits of
k-th Smallest in BST
Given a BST and an integer k, the task is to find the kth smallest element in the BST. If there is no kth
1910. Remove All Occurrences of a Substring
Given two strings s and part, perform the following operation on s until all occurrences of the substring part are removed: Find the leftmost occurrence of the substring part and remove it from s. Return s after removing
3174. Clear Digits
You are given a string s. Your task is to remove all digits by doing this operation repeatedly: Delete the first digit and the closest non-digit character to