Month: February 2021

Pseudo-Palindromic Paths in a Binary Tree

Given a binary tree where node values are digits from 1 to 9. A path in the binary tree is said to be pseudo-palindromic if at least one permutation of the node values in the path is a palindrome.

Combination Sum

Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

Add Two Numbers

Given two number represent by LinkedList, calculate the sum of the numbers and store the result in a new LinkedList. Each node of the linked list is represented by single-digit and the head node is the most significant digit.