CodeLab Fall 2021

Week 1

1. Multiply Strings https://leetcode.com/problems/multiply-strings/
2. String Compression https://leetcode.com/problems/string-compression/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/StringCompression/src/edu/northeastern/ashish/Main.java)
3. Implement strStr() https://leetcode.com/problems/implement-strstr/
4. Merge k Sorted Lists https://leetcode.com/problems/merge-k-sorted-lists/
5. Merge Sorted Array https://leetcode.com/problems/merge-sorted-array/
6. Kth Largest Element in an Array https://leetcode.com/problems/kth-largest-element-in-an-array/
7. Search in Rotated Sorted Array https://leetcode.com/problems/search-in-rotated-sorted-array/
8. Spiral Matrix https://leetcode.com/problems/spiral-matrix/
9. Merge Intervals https://leetcode.com/problems/merge-intervals/
10. 3 Sum https://leetcode.com/problems/3sum/
11. Subdomain Visit Count https://leetcode.com/problems/subdomain-visit-count/
12. Reconstruct Original Digits from English https://leetcode.com/problems/reconstruct-original-digits-from-english/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/ReconstructOriginalDigits/src/edu/northeastern/ashish/Main.java)
13. Expressive Words https://leetcode.com/problems/expressive-words/
14. Count Binary Substrings https://leetcode.com/problems/count-binary-substrings/
15. Roman to Integer https://leetcode.com/problems/roman-to-integer/
16. Sort Array by Increasing Frequency https://leetcode.com/problems/sort-array-by-increasing-frequency/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/SortByFrequency/src/edu/northeastern/ashish/Main.java)
17. Maximum Product of Three Numbers https://leetcode.com/problems/maximum-product-of-three-numbers/
18. Missing Number https://leetcode.com/problems/missing-number/
19. Contains Duplicate https://leetcode.com/problems/contains-duplicate/
20. Capacity To Ship Packages Within D Days https://leetcode.com/problems/capacity-to-ship-packages-within-d-days/
21. Rotate Array https://leetcode.com/problems/rotate-array/
22. Find Peak Element https://leetcode.com/problems/find-peak-element/
23. Move Zeroes https://leetcode.com/problems/move-zeroes/
24. Sort Colors https://leetcode.com/problems/sort-colors/
25. Find All Numbers Disappeared in an Array https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/
26. Product of Array Except Self https://leetcode.com/problems/product-of-array-except-self/
27. Add Strings https://leetcode.com/problems/add-strings/
28. Valid Palindrome II https://leetcode.com/problems/valid-palindrome-ii/
29. Reorganize String https://leetcode.com/problems/reorganize-string/
30. Longest Common Prefix https://leetcode.com/problems/longest-common-prefix/
31. Group Anagrams https://leetcode.com/problems/group-anagrams/
32. Set Matrix Zeroes https://leetcode.com/problems/set-matrix-zeroes/ [GitHub link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/SetMatrixToZeros/src/edu/northeastern/ashish/Main.java)
33. Longest Substring Without Repeating Characters https://leetcode.com/problems/longest-substring-without-repeating-characters/
34. Increasing Triplet Subsequence https://leetcode.com/problems/increasing-triplet-subsequence/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/IncreasingTripletSequence/src/edu/northeastern/ashish/Main.java)
35. Missing Ranges https://leetcode.com/problems/summary-ranges/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/SummaryRanges/src/edu/northeastern/ashish/Main.java)
36. Search for a Range https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/FindFirstAndLastPosition/src/edu/northeastern/ashish/Main.java)
37. First Bad Version https://leetcode.com/problems/first-bad-version/
38. Best Time to Buy and Sell Stock II https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/ [Github Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/BestTimeToBuyAndSellStock/src/edu/northeastern/ashish/Main.java)
39. Single Number https://leetcode.com/problems/single-number/ [Github link](https://github.com/HappyCoder29/CodeLab-Fall-2021/blob/main/SingleNumber/src/edu/northeastern/ashish/Main.java)
40. Remove Duplicates from Sorted Array https://leetcode.com/problems/remove-duplicates-from-sorted-array/ [GitHub Link](https://github.com/HappyCoder29/CodeLab-Fall-2021/tree/main/RemoveDuplicatesFromSortedArray/src/edu/northeastern/ashish)

Week 2

1. Valid Parentheses https://leetcode.com/problems/valid-parentheses/
2. Next Greater Element https://leetcode.com/problems/next-greater-element-i/
3. Daily Temperatures https://leetcode.com/problems/daily-temperatures/
4. Astroid Collision https://leetcode.com/problems/asteroid-collision/
5. Find the duplicate number https://leetcode.com/problems/find-the-duplicate-number/
6. Top K frequent Elements https://leetcode.com/problems/top-k-frequent-elements/
7. Buildings with an ocean view https://leetcode.com/problems/buildings-with-an-ocean-view/
8. Intersection of Two Arrays II https://leetcode.com/problems/intersection-of-two-arrays-ii/
9. Reverse Integer https://leetcode.com/problems/reverse-integer/
10. Plus One https://leetcode.com/problems/plus-one/
11. String Compression https://leetcode.com/problems/string-compression/
12. Container With Most Water https://leetcode.com/problems/container-with-most-water/
13. Minimum Remove to Make Valid Parentheses https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses/
14. Reorder Data in Log Files https://leetcode.com/problems/reorder-data-in-log-files/
15. Basic Calculator https://leetcode.com/problems/basic-calculator/
16. Next Greater Element II https://leetcode.com/problems/next-greater-element-ii/
17. Pascal's Triangle https://leetcode.com/problems/pascals-triangle/
18. Find All Anagrams in a String https://leetcode.com/problems/find-all-anagrams-in-a-string/solution/
19. Remove K Digits https://leetcode.com/problems/remove-k-digits/
20. Reverse Words in a String https://leetcode.com/problems/reverse-words-in-a-string/
21. Min Stack https://leetcode.com/problems/min-stack/
22. Max Stack https://leetcode.com/problems/max-stack/
23. Check If String Is a Prefix of Array https://leetcode.com/problems/check-if-string-is-a-prefix-of-array/
24. Decode String https://leetcode.com/problems/decode-string/
25. Backspace String Compare https://leetcode.com/problems/backspace-string-compare/
26. Remove All Adjacent Duplicates in String II https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii/
27. Find K Pairs with Smallest Sums https://leetcode.com/problems/find-k-pairs-with-smallest-sums/
28. Isomorphic Strings https://leetcode.com/problems/isomorphic-strings/
29. Maximum Product of Two Elements in an Array https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array/
30. Replace Elements with Greatest Element on Right Side https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/
31. Check If N and Its Double Exist https://leetcode.com/problems/check-if-n-and-its-double-exist/
32. Reverse String https://leetcode.com/problems/reverse-string/
33. Remove All Adjacent Duplicates In String https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/
34. Best Time to Buy and Sell Stock https://leetcode.com/problems/best-time-to-buy-and-sell-stock/
35. Implement Queue using Stacks https://leetcode.com/problems/implement-queue-using-stacks/
36. Sign of the Product of an Array https://leetcode.com/problems/sign-of-the-product-of-an-array/
37. Remove Duplicate Letters https://leetcode.com/problems/remove-duplicate-letters/
38. Verifying an Alien Dictionary https://leetcode.com/problems/verifying-an-alien-dictionary/
39. Valid Parentheses https://leetcode.com/problems/valid-parentheses/
40. Maximum Subarray https://leetcode.com/problems/maximum-subarray/
41. First Unique Character in a String https://leetcode.com/problems/first-unique-character-in-a-string/

Week 3

1. Maximum Depth of Binary Tree https://leetcode.com/problems/maximum-depth-of-binary-tree/solution/
2. Balanced Binary Tree https://leetcode.com/problems/balanced-binary-tree/
3. Palindrome Linked List https://leetcode.com/problems/palindrome-linked-list/solution/
4. Reverse Linked List II https://leetcode.com/problems/reverse-linked-list-ii/
5. Lowest Common Ancestor of a Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/solution/
6. Odd Even Linked List https://leetcode.com/problems/odd-even-linked-list/
7. Populating Next Right Pointers in Each Node https://leetcode.com/problems/populating-next-right-pointers-in-each-node/
8. Kth Smallest Element in a BST https://leetcode.com/problems/kth-smallest-element-in-a-bst/
9. Intersection of Two Linked Lists https://leetcode.com/problems/intersection-of-two-linked-lists/
10. Serialize and Deserialize Binary Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree/
11. Validate Binary Search Tree https://leetcode.com/problems/validate-binary-search-tree/
12. Delete Node in BST https://leetcode.com/problems/delete-node-in-a-bst/
13. Path Sum https://leetcode.com/problems/path-sum/
14. Diameter of Binary Tree https://leetcode.com/problems/diameter-of-binary-tree/
15. Range Sum Of BST https://leetcode.com/problems/range-sum-of-bst/
16. Linked List Cycle https://leetcode.com/problems/linked-list-cycle/
17. Add 2 Numbers https://leetcode.com/problems/add-two-numbers/
18. Rotate List https://leetcode.com/problems/rotate-list/
19. Reorder List https://leetcode.com/problems/reorder-list/
20. Insert into Sorted Circular Linked List https://leetcode.com/problems/insert-into-a-sorted-circular-linked-list/
21. Merge Two Sorted Lists https://leetcode.com/problems/merge-two-sorted-lists/
22. Add Two Numbers II https://leetcode.com/problems/add-two-numbers-ii/
23. Simplify Path https://leetcode.com/problems/simplify-path/
24. First Unique Character in a String https://leetcode.com/problems/first-unique-character-in-a-string/
25. Convert Binary Search Tree to Sorted Doubly Linked List https://leetcode.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-list/
26. Symmetric Tree https://leetcode.com/problems/symmetric-tree/
27. Increasing Order Search Tree https://leetcode.com/problems/increasing-order-search-tree/
28. Convert Sorted Array to Binary Search Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/
29. Invert Binary Tree https://leetcode.com/problems/invert-binary-tree/
30. Same Tree https://leetcode.com/problems/same-tree/
31. Partition List https://leetcode.com/problems/partition-list/
32. Plus One Linked List https://leetcode.com/problems/plus-one-linked-list/
33. Binary Tree Paths https://leetcode.com/problems/binary-tree-paths/
34. Binary Tree Right Side View https://leetcode.com/problems/binary-tree-right-side-view/
35. Swapping Nodes in a Linked List https://leetcode.com/problems/swapping-nodes-in-a-linked-list/
36. Sum of Left Leaves https://leetcode.com/problems/sum-of-left-leaves/
37. Reverse Nodes in k-Group https://leetcode.com/problems/reverse-nodes-in-k-group/
38. Binary Tree Vertical Order Traversal https://leetcode.com/problems/binary-tree-vertical-order-traversal/
39. Boundary of Binary Tree https://leetcode.com/problems/boundary-of-binary-tree/
40. Sort List https://leetcode.com/problems/sort-list/

## Week 4

1. Letter Combinations of a Phone Number https://leetcode.com/problems/letter-combinations-of-a-phone-number/
2. Reverse Nodes in k-Group https://leetcode.com/problems/reverse-nodes-in-k-group/
3. Search in Rotated Sorted Array https://leetcode.com/problems/search-in-rotated-sorted-array/
4. Wildcard Matching https://leetcode.com/problems/wildcard-matching/
5. Group Anagrams https://leetcode.com/problems/group-anagrams/
6. Spiral Matrix https://leetcode.com/problems/spiral-matrix/
7. Merge Intervals https://leetcode.com/problems/merge-intervals/
8. Word Search https://leetcode.com/problems/word-search/
9. Restore IP Addresses https://leetcode.com/problems/restore-ip-addresses/
10. Binary Tree Zigzag Level Order Traversal https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
11. LRU Cache https://leetcode.com/problems/lru-cache/
12. Reverse Words in a String https://leetcode.com/problems/reverse-words-in-a-string/
13. Read N Characters Given read4 II - Call Multiple Times https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times/
14. Number of Islands https://leetcode.com/problems/number-of-islands/
15. Course Schedule https://leetcode.com/problems/course-schedule/
16. Course Schedule II https://leetcode.com/problems/course-schedule-ii/
17. Word Search II https://leetcode.com/problems/word-search-ii/
18. Meeting Rooms II https://leetcode.com/problems/meeting-rooms-ii/
19. Integer to English Words https://leetcode.com/problems/integer-to-english-words/
20. Find the Celebrity https://leetcode.com/problems/find-the-celebrity/
21. Inorder Successor in BST https://leetcode.com/problems/inorder-successor-in-bst/
22. Find Median from Data Stream https://leetcode.com/problems/find-median-from-data-stream/
23. Serialize and Deserialize Binary Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree/
24. Longest Substring with At Most K Distinct Characters https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/
25. Design Tic-Tac-Toe https://leetcode.com/problems/design-tic-tac-toe/
26. String Compression https://leetcode.com/problems/string-compression/
27. Minimum Moves to Equal Array Elements II https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/
28. Validate IP Address https://leetcode.com/problems/validate-ip-address/
29. Single Element in a Sorted Array https://leetcode.com/problems/single-element-in-a-sorted-array/
30. Boundary of Binary Tree https://leetcode.com/problems/boundary-of-binary-tree/
31. Design In-Memory File System https://leetcode.com/problems/design-in-memory-file-system/
32. Design Circular Queue https://leetcode.com/problems/design-circular-queue/
33. Design Search Autocomplete System https://leetcode.com/problems/design-search-autocomplete-system/
34. Design HashMap https://leetcode.com/problems/design-hashmap/
35. Max Stack https://leetcode.com/problems/max-stack/
36. Max Chunks To Make Sorted II https://leetcode.com/problems/max-chunks-to-make-sorted-ii/
37. Max Chunks To Make Sorted https://leetcode.com/problems/max-chunks-to-make-sorted/
38. Maximum Frequency Stack https://leetcode.com/problems/maximum-frequency-stack/
39. Partition Array into Disjoint Intervals https://leetcode.com/problems/partition-array-into-disjoint-intervals/
40. Distribute Coins in Binary Tree https://leetcode.com/problems/distribute-coins-in-binary-tree/
41. Find Winner on a Tic Tac Toe Game https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game/
42. Find N Unique Integers Sum up to Zero https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/
43. Minimum Insertion Steps to Make a String Palindrome https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome/
44. Angle Between Hands of a Clock https://leetcode.com/problems/angle-between-hands-of-a-clock/
45. Longest Happy String https://leetcode.com/problems/longest-happy-string/
46. Count Good Nodes in Binary Tree https://leetcode.com/problems/count-good-nodes-in-binary-tree/
47. Minimum Deletion Cost to Avoid Repeating Letters https://leetcode.com/problems/count-good-nodes-in-binary-tree/
48. Maximal Network Rank https://leetcode.com/problems/maximal-network-rank/
49. Minimum Deletions to Make Character Frequencies Unique https://leetcode.com/problems/minimum-deletion-cost-to-avoid-repeating-letters/
50. Sign of the Product of an Array https://leetcode.com/problems/sign-of-the-product-of-an-array/