Day 1

	Problem	Companies	Tags
1.	Two Sum	Facebook	math
2.	Valid Parentheses	Facebook, Google, Microsoft	counting
3.	Reverse Linked List	Facebook	link_list
4.	Binary Tree Level Order Traversal	Facebook	tree, bst, bfs
5.	First Bad Version	Facebook	search, binary_search

Day 2

	Problem	Companies	Tags
1.	Remove duplicates from a sorted array	Facebook, Microsoft	array, pointers
2.	Valid Palindrome	Facebook, Microsoft	array, pointers
3.	Excel Sheet Column Title	Facebook, Microsoft	math
4.	Implement strStr()	Facebook	string, search
5.	Lowest Common Ancestor of a Binary Search Tree	Facebook	tree, bst,dfs

Day 3

	Problem	Companies	Tags
1.	Best Time to Buy and Sell Stock	Facebook, Google	pointer
2.	Binary Tree Paths	Facebook, Google	tree, bst
3.	Merge Two Sorted Lists	Facebook, Microsoft	link_list
4.	Min Stack	Google	oop, stack
5.	Validate Binary Search Tree	Facebook, Google	tree, bst, dfs

Day 4

	Problem	Companies	Tags
1.	Task Scheduler	Facebook	pointer
2.	Palindrome Permutation	Google	string, pattern
3.	Closest Binary Search Tree Value	Google	tree, bst
4.	Implement Trie (Prefix Tree)	Facebook, Google	tree, oop
5.	Palindrome Linked List	Facebook	tree, bst, dfs

Day 5

	Problem	Companies	Tags
1.	Task Scheduler	Facebook	pointer
2.	Palindrome Permutation	Google	string, pattern
3.	Closest Binary Search Tree Value	Google	tree, bst
4.	Implement Trie (Prefix Tree)	Facebook, Google	tree, oop
5.	Palindrome Linked List	Facebook	tree, bst, dfs

Day 6

	Problem	Companies	Tags
1.	Diameter of Binary Tree	Facebook	pointer
2.	Valid Palindrome II	Facebook	string, pattern
3.	Longest Continuous Increasing Subsequence	Facebook	math, bst
4.	Encode and Decode TinyURL	Facebook	oop, system_design, hashing

Day 7

	Problem	Companies	Tags
1.	Friend Circles	Facebook, Microsoft	graph
2.	Count and Say	Facebook, Microsoft	string, pattern, math
3.	LFU Cache	Facebook, Google	math, bst
4.	Sum of Left Leaves	Facebook, Google	tree, bst
5.	Fibonacci Number	Facebook, Google	recursion, dynamic_programming