# LeetCode 1920. Build Array from Permutation

Description https://leetcode.com/problems/build-array-from-permutation/ Given a zero-based permutation nums (0-indexed), build an array ans of the same length where ans[i] = nums[nums[i]] for each 0 <= i < nums.length and return it. A zero-based…

# LeetCode 295. Find Median from Data Stream

Description https://leetcode.com/problems/find-median-from-data-stream/ The median is the middle value in an ordered integer list. If the size of the list is even, there…

# LeetCode 143. Reorder List

Description https://leetcode.com/problems/reorder-list/ You are given the head of a singly linked-list. The list can be represented as: L0 → L1…

# LeetCode 235. Lowest Common Ancestor of a Binary Search Tree

Description https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/ Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the…

# LeetCode 114. Flatten Binary Tree to Linked List

Description https://leetcode.com/problems/flatten-binary-tree-to-linked-list/ Given the root of a binary tree, flatten the tree into a “linked list”: The “linked list” should use the…

# LeetCode 47. Permutations II

Description https://leetcode.com/problems/permutations-ii/ Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order. Example 1: Input: nums…

# LeetCode 426. Convert Binary Search Tree to Sorted Doubly Linked List

Description https://leetcode.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-list/ Convert a Binary Search Tree to a sorted Circular Doubly-Linked List in place. You can think of the left and right pointers…

# Get Well Prepared for Facebook

Total 79 questions. Introduction “Interviewing for a technical job is hard, and so is being the interviewer. You want to…

# LeetCode 721. Accounts Merge

Description https://leetcode.com/problems/accounts-merge/ Given a list of accounts where each element accounts[i] is a list of strings, where the first element accounts[i][0] is a name, and the…

# LeetCode 236. Lowest Common Ancestor of a Binary Tree

Description https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According…