Nine notes

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.

Given an array containing n distinct numbers taken from 0, 1, 2, …, n, find the one that is missing from the array.

For example,
Given nums = [0, 1, 3] return 2.

Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?

There are N children standing in a line. Each child is assigned a rating value.

Design a data structure that supports the following two operations:

Implement a trie with insert, search, and startsWith methods.

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.

Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.

Given a linked list, determine if it has a cycle in it.

Given a collection of intervals, merge all overlapping intervals.

Given an array of integers, every element appears three times except for one. Find that single one.

Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).

Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.