day 1 => 1. Two Sum
day 2 => 9. Palindrome Number
day 3=> 13. Roman to integer
day 4 => 14. Longest Common Prefix
day 5 => 20. Valid Parentheses
day 6 => 21. Merge Two Sorted List
day 7 => 26. Remove Duplicates From Sorted Array
day 8 => 26. Remove Element
day 9 => 28. Find the Index of the First Occurrence in a String
day 10 => 35. Search Insert Position
day 11 => 58. Length of Last Word
day 13 => 66. Plus One
day 14 => 67. Add Binary
day 15 => 69. Sqrt(x)
day 16 => 70. Climbing Stairs
day 17 => 83. Remove Duplicates from Sorted List
day 18 => 100. Same Tree
day 19 => 136. Single Number
day 20 => 141. Linked List Cycle
day 21 => 160. Intersection of Two Linked Lists
day 22 => 203. Remove Linked List Elements
day 23 => 876. Middle of the Linked List
day 24 => 206. Reverse Linked List
day 25 => 234. Palindrome Linked List
day 26=> 231. Power of two
day 27=> 258. Add Digits
day 28=> 263. Ugly Number
day 29=> 268. Missing Number
day 12 => 2. Add Two Numbers