LC 25 Reverse Nodes in k-Group (Linked List) | O(1)
Reverse linked list in k groups (Hard): in-place pointer reversal with dummy node. Optimal O(n) time, O(1) space—step-by-step solution.
Palindrome Linked List
Check if a linked list is a palindrome using O(1) extra space
Reorder List
Reorder a linked list by interleaving nodes from the beginning and end
Reverse Bits
Reverse the bits of a given 32-bit unsigned integer.
Reverse String
Reverse a string in-place using O(1) extra memory.