Linked List

Linked-list problems are about pointer manipulation — reversing, merging, splitting, and detecting structure — without random access. The classic tools are a dummy head node, careful next-pointer rewiring, and two pointers.

18 LeetCode problems solved with the Linked List pattern. Practice them with spaced repetition so the pattern sticks.

• Add Two NumbersMEDIUM · O(max(m, n))
• Copy List with Random PointerMEDIUM · O(n)
• Design Linked ListMEDIUM · O(index)
• Insert Greatest Common Divisors in Linked ListMEDIUM · O(n log M)
• Intersection of Two Linked ListsEASY · O(m + n)
• Maximum Twin Sum of a Linked ListMEDIUM · O(n)
• Merge Two Sorted ListsEASY · O(n + m)
• Odd Even Linked ListMEDIUM · O(n)
• Partition ListMEDIUM · O(n)
• Remove Duplicates from Sorted List IIMEDIUM · O(n)
• Remove Linked List ElementsEASY · O(n)
• Remove Nth Node From End of ListMEDIUM · O(n)
• Reorder ListMEDIUM · O(n)
• Reverse Linked ListEASY · O(n)
• Reverse Linked List IIMEDIUM · O(n)
• Reverse Nodes in k-GroupHARD · O(n)
• Rotate ListMEDIUM · O(n)
• Swap Nodes in PairsMEDIUM · O(n)