Grind75 Solutions & Resources: JavaScript

As I work through this list I figure I would make a GitHub repo with my solutions along with articles and videos that relate to the problems that I've found helpful.

The problems

Easy

1. Two Sum #1
2. Valid Parentheses #20
3. Merge Two Sorted Lists #21
4. Best Time to Buy and Sell Stock #121
5. Valid Palindrome #125
6. Invert Binary Tree #226
7. Valid Anagram #242
8. Binary Search #704
9. Flood Fill #733
10. Lowest Common Ancestor of a Binary Search Tree #235
11. Balanced Binary Tree #110
12. Linked List Cycle #141
13. Implement Queue using Stacks #232
14. First Bad Version #278
15. Ransom Note #383
16. Climbing Stairs #70
17. Longest Palindrome #409
18. Reverse Linked List #206
19. Majority Element #169
20. Add Binary #67
21. Diameter of Binary Tree #543
22. Middle of the Linked List #876
23. Maximum Depth of Binary Tree #104
24. Contains Duplicate #217

Medium

25. Maximum Subarray #53
26. Insert Interval #57
27. 01 Matrix #542
28. K Closest Points to Origin #973
29. Longest Substring Without Repeating Characters #3
30. 3Sum #15
31. Binary Tree Level Order Traversal #102
32. Clone Graph #133
33. Evaluate Reverse Polish Notation #150
34. Course Schedule #207
35. Implement Trie (Prefix Tree) #208
36. Coin Change #322
37. Product of Array Except Self #238
38. Min Stack #155
39. Validate Binary Search Tree #98
40. Number of Islands #200
41. Rotting Oranges #994
42. Search in Rotated Sorted Array #33
43. Combination Sum #39
44. Permutations #46
45. Merge Intervals #56
46. Lowest Common Ancestor of a Binary Tree #236
47. Time Based Key-Value Store #981
48. Accounts Merge #721
49. Sort Colors #75
50. Word Break #139
51. Partition Equal Subset Sum #416
52. String to Integer (atoi) #8
53. Spiral Matrix #54
54. Subsets #78
55. Binary Tree Right Side View #199
56. Longest Palindromic Substring #5
57. Unique Paths #62
58. Construct Binary Tree from Preorder and Inorder Traversal #105
59. Container With Most Water #11
60. Letter Combinations of a Phone Number #17
61. Word Search #79
62. Find All Anagrams in a String #438
63. Minimum Height Trees #310
64. Task Scheduler #621
65. LRU Cache #146
66. Kth Smallest Element in a BST #230

Hard

67. Minimum Window Substring #76
68. Serialize and Deserialize Binary Tree #297
69. Trapping Rain Water #42
70. Find Median from Data Stream #295
71. Word Ladder #127
72. Basic Calculator #224
73. Maximum Profit in Job Scheduling #1235
74. Merge k Sorted Lists #23
75. Largest Rectangle in Histogram #84

Data Structures

In order to practice with similar data structures I'll be placing each problem in the categories below, along with some similar problems nested below to help practice with those data structures.

Array

• Two Sum #1
• Best Time to Buy and Sell Stock #121
• Binary Search #704
• Flood Fill #733
• Maximum Subarray #53
• Majority Element #169
• Contains Duplicate #217
• K Closest Points to Origin #973
• Insert Interval #57
• 01 Matrix #542
• 3Sum #15
• Merge Intervals #56
• Evaluate Reverse Polish Notation #150
• Maximum Units on a Truck #1710
• Meeting Rooms II
• Coin Change #322
• Product of Array Except Self #238
• Number of Islands #200
• Rotting Oranges #994
• Search in Rotated Sorted Array #33
• Combination Sum #39
• Trapping Rain Water #42

Queue

• Invert Binary Tree #226
• Flood Fill #733
• Implement Queue using Stacks #232
• Maximum Depth of Binary Tree #104
• Binary Tree Level Order Traversal #102
• Coin Change #322
• Number of Islands #200
• Rotting Oranges #994

Stack

• Valid Parentheses #20
• Invert Binary Tree #226
• Flood Fill #733
• Implement Queue using Stacks #232
• Maximum Depth of Binary Tree #104
• Evaluate Reverse Polish Notation #150
• Min Stack #155
• Validate Binary Search Tree #98
• Number of Islands #200

Linked Lists

• Merge Two Sorted Lists #21
• Convert Binary Number in a Linked List to Integer #1290
• Linked List Cycle #141
• Reverse Linked List #206
• Middle of the Linked List #876
• LRU Cache #146
• Merge k Sorted Lists #23

Hash Table

• Two Sum #1
• Valid Parentheses #20
• Valid Anagram #242
• Linked List Cycle #141
• Ransom Note #383
• Climbing Stairs #70
• Longest Palindrome #409
• Majority Element #169
• Contains Duplicate #217
• Longest Substring Without Repeating Characters #3
• 3Sum #15
• Clone Graph #133
• LRU Cache #146
• Implement Trie (Prefix Tree) #208

Binary Tree

• Invert Binary Tree #226
• Lowest Common Ancestor of a Binary Search Tree #235
• Balanced Binary Tree #110
• Diameter of Binary Tree #543
• Maximum Depth of Binary Tree #104
• Binary Tree Level Order Traversal #102
• Validate Binary Search Tree #98

Graph

• Clone Graph #133
• Number of Provinces #547
• Course Schedule #207

Heap

• K Closest Points to Origin #973
• Meeting Rooms II

Trie

• Implement Trie (Prefix Tree) #208

Algorithm Patterns

Within the problems above there are several patterns that often occur. I plan to categorize each problem such that if you are having problem with a particular pattern you can look for other similar problems that use the same pattern.

Two Pointers

• Best Time to Buy and Sell Stock #121
• Valid Palindrome #125
• Linked List Cycle #141
• Reverse Linked List #206
• Middle of the Linked List #876
• Contains Duplicate #217
• 3Sum #15
• Meeting Rooms II
• Trapping Rain Water #42

Sliding Window

• Longest Substring Without Repeating Characters #3

Binary Search

• First Bad Version #278
• Search in Rotated Sorted Array #33

Breadth First Search

• Invert Binary Tree #226
• Flood Fill #733
• Maximum Depth of Binary Tree #104
• 01 Matrix #542
• Binary Tree Level Order Traversal #102
• Clone Graph #133
• Number of Provinces #547
• Course Schedule #207
• Coin Change #322
• Number of Islands #200
• Rotting Oranges #994

Depth First Search

• Invert Binary Tree #226
• Flood Fill #733
• Lowest Common Ancestor of a Binary Search Tree #235
• Balanced Binary Tree #110
• Diameter of Binary Tree #543
• Maximum Depth of Binary Tree #104
• Clone Graph #133
• Number of Provinces #547
• Course Schedule #207
• Validate Binary Search Tree #98
• Number of Islands #200
• Combination Sum #39

Divide & Conquer

• Maximum Subarray #53
• Merge k Sorted Lists #23

Dynamic Programming

• Maximum Subarray #53
• 01 Matrix #542
• Coin Change #322
• Trapping Rain Water #42

Attribution

• The original Grind 75 list can be found here