January 2021 LeetCoding Challenge Day Question Links Solutions 1. Check Array Formation Through Concatenation cpp 2. Find a Corresponding Node of a Binary Tree in a Clone of That Tree cpp 3. Beautiful Arrangement cpp 4. Merge Two Sorted Lists cpp 5. Remove Duplicates from Sorted List II cpp 6. Kth Missing Positive Number cpp 7. Longest Substring Without Repeating Characters cpp 8. Check If Two String Arrays are Equivalent cpp 9. Word Ladder cpp 10. Create Sorted Array through Instructions cpp 11. Merge Sorted Array cpp 12. Add Two Numbers cpp 13. Boats to Save People cpp 14. Minimum Operations to Reduce X to Zero cpp 15. Get Maximum in Generated Array cpp 16. Kth Largest Element in an Array cpp 17. Count Sorted Vowel Strings cpp 18. Max Number of K-Sum Pairs cpp 19. Longest Palindromic Substring cpp 20. Valid Parentheses cpp 21. Find the Most Competitive Subsequence cpp 22. Determine if Two Strings Are Close cpp 23. Sort the Matrix Diagonally cpp 24. Merge k Sorted Lists cpp 25. 1's Are at Least Length K Places Away cpp 26. Path With Minimum Effort cpp 27. Concatenation of Consecutive Binary Numbers cpp 28. Smallest String With A Given Numeric Value cpp 29. Vertical Order Traversal of a Binary Tree cpp 30. Minimize Deviation in Array cpp 31. Next Permutation cpp