studying_leetcode

Notes for technical interview

Setup

We will actually start with specific data structures and break into patterns via Data structures/algorithm tech handbook and then using Neetcode as hollistic reference. Then we will add Neetcode afterwards. A master list of all the leetcode problems completed and organized afterwards by data structures.

Problem List

Arrays

LeetCode Number	Problem	Difficulty
1	Two Sum	${\color{green}Easy}$
121	Best Time to Buy and Sell Stock	${\color{green}Easy}$
238	Product of Array Except Self	${\color{orange}Medium}$
53	Maximum Subarray	${\color{orange}Medium}$
242	Valid Anagram	${\color{green}Easy}$
125	Valid Palindrome	${\color{green}Easy}$
3	Longest Substring Without Repeating Characters	${\color{orange}Medium}$
217	Contains Duplicate	${\color{green}Easy}$
152	Maximum Product Subarray	${\color{orange}Medium}$
33	Search in Rotated Sorted Array	${\color{orange}Medium}$
15	3Sum	${\color{orange}Medium}$
11	Container with Most Water	${\color{orange}Medium}$
239	Sliding Window Maximum	${\color{Red}Hard}$
424	Longest Repeating Character Replacement	${\color{orange}Medium}$
438	Find All Anagrams in a String	${\color{orange}Medium}$
76	Minimum Window Substring	${\color{Red}Hard}$
49	Group Anagrams	${\color{orange}Medium}$
5	Longest Palindromic Substring	${\color{orange}Medium}$
271	Encode and Decode Strings	${\color{orange}Medium}$

Hash Tables

LeetCode Number	Problem	Difficulty
1	Two Sum	${\color{green}Easy}$
383	Ransom Note	${\color{green}Easy}$
49	Group Anagrams	${\color{orange}Medium}$
41	First Missing Positive	${\color{Red}Hard}$
146	LRU Cache	${\color{orange}Medium}$
432	All O' one Data Structure	${\color{Red}Hard}$

Recursion

LeetCode Number	Problem	Difficulty
22	Generate Parenthesis	${\color{orange}Medium}$
77	Combinations	${\color{orange}Medium}$
78	Subsets	${\color{orange}Medium}$
17	Letter Combinations of a Phone Number	${\color{orange}Medium}$
90	Subsets II	${\color{orange}Medium}$
46	Permutations	${\color{orange}Medium}$
37	Sudoku Solver	${\color{Red}Hard}$
247	Strobogrammatic Number II	${\color{orange}Medium}$

Sorting and Searching

LeetCode Number	Problem	Difficulty
704	Binary Search	${\color{green}Easy}$
33	Search in Rotated Sorted Array	${\color{orange}Medium}$
378	Kth Smallest Element in a Sorted Matrix	${\color{orange}Medium}$
74	Search a 2D Matrix	${\color{orange}Medium}$
215	Kth Largest Element in an Array	${\color{orange}Medium}$
153	Find Minimum in Rotated Sorted Array	${\color{orange}Medium}$
4	Median of Two Sorted Arrays	${\color{Red}Hard}$

Matrices

LeetCode Number	Problem	Difficulty
73	Set Matrix Zeroes	${\color{orange}Medium}$
54	Spiral Matrix	${\color{orange}Medium}$
48	Rotate Image	${\color{orange}Medium}$
36	Valid Sudoku	${\color{orange}Medium}$

Linked Lists

LeetCode Number	Problem	Difficulty
206	Reverse Linked List	${\color{green}Easy}$
141	Linked List Cycle	${\color{green}Easy}$
21	Merge Two Sorted Lists	${\color{green}Easy}$
23	Merge K Sorted Lists	${\color{Red}Hard}$
19	Remove Nth Node from End of List	${\color{orange}Medium}$
143	Reorder List	${\color{orange}Medium}$

Queue

LeetCode Number	Problem	Difficulty
225	Implement Stack Using Queues	${\color{green}Easy}$
232	Implement Queue Using Stacks	${\color{green}Easy}$
622	Design Circular Queue	${\color{orange}Medium}$
362	Design Hit Counter	${\color{orange}Medium}$

Stacks

LeetCode Number	Problem	Difficulty
20	Valid Parentheses	${\color{green}Easy}$
232	Implement Queue Using Stacks	${\color{green}Easy}$
225	Implement Stack Using Queues	${\color{green}Easy}$
155	Min Stack	${\color{orange}Medium}$
735	Asteroid Collision	${\color{orange}Medium}$
150	Evaluate Reverse Polish Notation	${\color{orange}Medium}$
224	Basic Calculator	${\color{Red}Hard}$
227	Basic Calculator II	${\color{orange}Medium}$
739	Daily Temperatures	${\color{orange}Medium}$
42	Trapping Rain Water	${\color{Red}Hard}$
84	Largest Rectangle in Histogram	${\color{Red}Hard}$

Intervals

LeetCode Number	Problem	Difficulty
56	Merge Intervals	${\color{orange}Medium}$
57	Insert Interval	${\color{orange}Medium}$
435	Non-Overlapping Intervals	${\color{orange}Medium}$
252	Meeting Rooms	${\color{green}Easy}$
253	Meeting Rooms II	${\color{orange}Medium}$

Trees

LeetCode Number	Problem	Difficulty
104	Maximum Depth of Binary Tree	${\color{green}Easy}$
226	Invert Binary Tree	${\color{green}Easy}$
235	Lowest Common Ancestor of a Binary Search Tree	${\color{orange}Medium}$
100	Same Tree	${\color{green}Easy}$
124	Binary Tree Maximum Path Sum	${\color{Red}Hard}$
102	Binary Tree Level Order Traversal	${\color{orange}Medium}$
236	Lowest Common Ancestor of a Binary Tree	${\color{orange}Medium}$

Graphs

LeetCode Number	Problem	Difficulty
200	Number of Islands	${\color{orange}Medium}$
733	Flood Fill	${\color{green}Easy}$
542	01 Matrix	${\color{orange}Medium}$

Heaps

LeetCode Number	Problem	Difficulty
23	Merge k Sorted Lists	${\color{Red}Hard}$
973	K Closest Points to Origin	${\color{orange}Medium}$

Tries

LeetCode Number	Problem	Difficulty
208	Implement Trie (Prefix Tree)	${\color{orange}Medium}$

Dynamic Programming

LeetCode Number	Problem	Difficulty
70	Climbing Stairs	${\color{green}Easy}$
322	Coin Change	${\color{orange}Medium}$
198	House Robber	${\color{orange}Medium}$
300	Longest Increasing Subsequence	${\color{orange}Medium}$

Patterns

1. Two Pointers

1. Introduction

2. Fast & Slow Pointers

1. Introduction

3. Sliding Window

1. Introduction

4. Merging Intervals

1. Introduction

5. Cyclic Sort

1. Introduction

6. In-Place Reversal of a Linked List

1. Introduction

7. Stack

1. Introduction

8. Monotonic Stack

1. Introduction

9. Hash Maps

1. Introduction

10. Tree Breadth First Search

1. [Introduction]

11. Tree Depth First Search

1. [Introduction]

12. Graphs

13. Island (Matrix Traversal)

14. Two Heaps

15. Subsets

16. Modified Binary Search

17. Bitwise XOR

18. Top 'K' Elements

19. K-Way Merge

20. Greedy Algorithms

21. 0/1 Knapsack (Dynamic Programming)

22. Backtracking

23. Trie

24. Topological Sort (Graph)

25. Union Find

26. Ordered Set

27. Multi-Thread