Leetcode

For LeetCode beginners, their understanding of the problems can be used for review and to showcase mine thinking process.

My Leetcode Personal Proflie

https://leetcode.com/u/bohemian0966/

My score

My Learning Path

|🟢Easy| |🟠Medium| |🔴Hard| C++|

|XX||🟠Medium|C++|

⭐ : The problem that is prefect for this theme

Hashing (Hashing Table)

Difficult: 🧠

#	Title	Difficulty	Solution
1	Two Sum	🟢Easy	C++
13	Roman to Integer	🟢Easy	C++
49	Group Anagrams	🟠Medium⭐	C++
149	max-points-on-a-line	🔴Hard⭐	C++
1657	determine-if-two-strings-are-close	🟠Medium	C++

Two Pointer

Difficult: 🧠

#	Title	Difficulty	Solution
125	valid-palindrome	🟢Easy	C++
11	container-with-most-water	🟠Medium	C++
1679	max-number-of-k-sum-pairs	🟠Medium	C++
2540	minimum-common-value	🟠Medium⭐	C++

Sliding window

Warning : In order to understand this chapter, you must first have read Two Pointer Difficult: 🧠🧠

#	Title	Difficulty	Solution
713	Subarray Product Less Than K	🟠Medium	C++

Stack

Difficult: 🧠🧠

#	Title	Difficulty	Solution
2390	removing-stars-from-a-string	🟠Medium⭐	C++
735	asteroid-collision	🟠Medium	C++
394	decode-string	🟠Medium	C++
150	evaluate-reverse-polish-notation	🟠Medium	C++
739	daily-temperatures	🟠Medium⭐	C++

Queue

Difficult: 🧠🧠

#	Title	Difficulty	Solution
649	dota2-senate	🟠Medium	C++
621	task-scheduler	🟠Medium	C++

Priority_Queue

Warning : In order to understand this chapter, you must first have read Queue

Difficult: 🧠🧠

#	Title	Difficulty	Solution

Backtracking

Difficult: 🧠🧠🧠

#	Title	Difficulty	Solution
17	letter-combinations-of-a-phone-number	🟠Medium	C++
39	combination-sum	🟠Medium	C++
40	combination-sum-ii	🟠Medium⭐	C++
37	sudoku-solver	🔴Hard⭐	C++
51	n-queens	🔴Hard⭐	C++
52	n-queens-ii	🔴Hard	C++
980	unique-paths-iii	🔴Hard	C++

Set

Difficult: 🧠🧠

#	Title	Difficulty	Solution
442	find-all-duplicates-in-an-array	🟠Medium	C++
3002	maximum-size-of-a-set-after-removals	🟠Medium⭐	C++
		🟠Medium	C++
		🟠Medium	C++

Linked_List

Warning : In order to understand this chapter, you must first have known about pointer

Difficult: 🧠🧠 - 🧠🧠🧠

#	Title	Difficulty	Solution
141	linked-list-cycle	🟢Easy	C++
92	reverse-linked-list-ii	🟠Medium	C++
25	reverse-nodes-in-k-group	🔴Hard	C++
19	remove-nth-node-from-end-of-list	🟠Medium⭐	C++
146	lru-cache	🟠Medium⭐	C++
2130	maximum-twin-sum-of-a-linked-list	🟠Medium	C++
XX		🟠Medium	C++

Tree

Warning : In order to understand this chapter, you must first have read Linked_List

Difficult: 🧠🧠 - 🧠🧠🧠

#	Title	Difficulty	Solution
2196	Create Binary Tree From Descriptions	🟠Medium	C++
1110	Delete Nodes And Return Forest	🟠Medium	C++

Binary Search

Warning : In order to understand this chapter, you must first have read Tree

Difficult: 🧠🧠

#	Title	Difficulty	Solution

Prefix Sum

Warning : In order to understand this chapter, you must first have read Two_pointer and Map (or hashtable)

Difficult: 🧠🧠 - 🧠🧠🧠

#	Title	Difficulty	Solution

Brain teaser

Difficult: 🧠 - 🧠🧠🧠

#	Title	Difficulty	Solution
1653	minimum-deletions-to-make-string-balanced	🟠Medium	C++
128	longest-consecutive-sequence	🟠Medium	C++
289	game-of-life	🟠Medium	C++
41	first-missing-positive	🔴Hard	C++