Grind 75
===
- 1. [Two Sum](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/rkpMM7M2j)
Easy

- 2. [Valid Parentheses](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/SkMzz7d3j)
Easy

- 3. [Merge Two Sorted Lists](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/S1GZrmuhi)
Easy

- 4. [Best Time to Buy and Sell Stock](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/ByP2gBY2o)
Easy

- 5. [Valid Palindrome](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/B1RISIF2s)
Easy

- 6. [Invert Binary Tree](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/ry74Sj712)
Easy

7
[Valid Anagram](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/S1wThds1n)
Easy

8
Binary Search
Easy
·
15 mins

9
Flood Fill
Easy
·
20 mins

10
Lowest Common Ancestor of a Binary Search Tree
Easy
·
20 mins

11
Balanced Binary Tree
Easy
·
15 mins

12
Linked List Cycle
Easy
·
20 mins

13
Implement Queue using Stacks
Easy
·
20 mins

1
First Bad Version
Easy
·
20 mins

2
[Ransom Note](https://hackmd.io/@RAHYy1QGQMeKNR10uK2unQ/rJvCOj7kh)
Easy

3
Climbing Stairs
Easy
·
20 mins

4
Longest Palindrome
Easy
·
20 mins

5
Reverse Linked List
Easy
·
20 mins

6
Majority Element
Easy
·
20 mins

7
Add Binary
Easy
·
15 mins

8
Diameter of Binary Tree
Easy
·
30 mins

9
Middle of the Linked List
Easy
·
20 mins

10
Maximum Depth of Binary Tree
Easy
·
15 mins

11
Contains Duplicate
Easy
·
15 mins

12
Maximum Subarray
Medium
·
20 mins

1
Insert Interval
Medium
·
25 mins

2
01 Matrix
Medium
·
30 mins

3
K Closest Points to Origin
Medium
·
30 mins

4
Longest Substring Without Repeating Characters
Medium
·
30 mins

5
3Sum
Medium
·
30 mins

6
Binary Tree Level Order Traversal
Medium
·
20 mins

7
Clone Graph
Medium
·
25 mins

8
Evaluate Reverse Polish Notation
Medium
·
30 mins

1
Course Schedule
Medium
·
30 mins

2
Implement Trie (Prefix Tree)
Medium
·
35 mins

3
Coin Change
Medium
·
25 mins

4
Product of Array Except Self
Medium
·
30 mins

5
Min Stack
Medium
·
20 mins

6
Validate Binary Search Tree
Medium
·
20 mins

7
Number of Islands
Medium
·
25 mins

8
Rotting Oranges
Medium
·
30 mins

1
Search in Rotated Sorted Array
Medium
·
30 mins

2
Combination Sum
Medium
·
30 mins

3
Permutations
Medium
·
30 mins

4
Merge Intervals
Medium
·
30 mins

5
Lowest Common Ancestor of a Binary Tree
Medium
·
25 mins

6
Time Based Key-Value Store
Medium
·
35 mins

7
Accounts Merge
Medium
·
30 mins

8
Sort Colors
Medium
·
25 mins

1
Word Break
Medium
·
30 mins

2
Partition Equal Subset Sum
Medium
·
30 mins

3
String to Integer (atoi)
Medium
·
25 mins

4
Spiral Matrix
Medium
·
25 mins

5
Subsets
Medium
·
30 mins

6
Binary Tree Right Side View
Medium
·
20 mins

7
Longest Palindromic Substring
Medium
·
25 mins

8
Unique Paths
Medium
·
20 mins

9
Construct Binary Tree from Preorder and Inorder Traversal
Medium
·
25 mins

1
Container With Most Water
Medium
·
35 mins

2
Letter Combinations of a Phone Number
Medium
·
30 mins

3
Word Search
Medium
·
30 mins

4
Find All Anagrams in a String
Medium
·
30 mins

5
Minimum Height Trees
Medium
·
30 mins

6
Task Scheduler
Medium
·
35 mins

7
LRU Cache
Medium
·
30 mins

1
Kth Smallest Element in a BST
Medium
·
25 mins

2
Minimum Window Substring
Hard
·
30 mins

3
Serialize and Deserialize Binary Tree
Hard
·
40 mins

4
Trapping Rain Water
Hard
·
35 mins

5
Find Median from Data Stream
Hard
·
30 mins

6
Word Ladder
Hard
·
45 mins

7
Basic Calculator
Hard
·
40 mins

8
Maximum Profit in Job Scheduling
Hard
·
45 mins

9
Merge k Sorted Lists
Hard
·
30 mins

10
Largest Rectangle in Histogram
Hard
·
35 mins