Hashing problems

4 Hashing DSA practice problems on CampusCode, each with statement, examples and constraints.

• 337. Remove Duplicates from Unsorted Linked List Easy Linked List
• 343. Find Pair with Given Sum in Doubly Linked List Easy Linked List
• 445. Find Smallest Common Element in All Rows Easy Binary Search
• 1312. Pairs with XOR Equal to K Easy Bit Manipulation