7 articles
LC 21 Merge Two Sorted Lists is one of the most frequently asked linked list interview problems at Amazon, Google, and Microsoft. Learn the dummy head merge pattern with step-by-step Python and JavaScript solutions, visual dry run, and interview tips.
LC 203 Remove Linked List Elements is a fundamental interview problem asked at Google and Amazon that teaches the dummy head sentinel pattern for handling head deletion cleanly. Learn O(n) solutions in Python and JavaScript with visual dry run, common mistakes, and recursive variant.
LC 19 Remove Nth Node From End of List is a classic one-pass interview problem at Amazon, Google, and Facebook that combines the dummy head sentinel with a two-pointer n-gap technique. Learn the optimal O(n) single-pass solution with Python and JavaScript, step-by-step dry run, and common interview traps.
LC 24 Swap Nodes in Pairs is a medium linked list interview problem at Microsoft and Bloomberg that tests precise multi-step pointer manipulation. Learn the iterative dummy-head approach and the recursive solution with Python and JavaScript, detailed visual dry run, and interview tips.
LC 2 Add Two Numbers is one of the most iconic interview problems at Amazon, Google, and Microsoft where you simulate grade-school addition on two reversed linked lists digit by digit. Master the carry propagation technique with Python and JavaScript solutions, visual dry run, and common pitfalls.
LC 86 Partition List is a medium interview problem at Bloomberg and Amazon that extends the dummy-head two-chain pattern to partition by value comparison. Learn the stable O(n) solution with Python and JavaScript, visual dry run, and critical edge cases including the tail-cycle trap.
LC 82 Remove Duplicates from Sorted List II is a medium interview problem at Google, Amazon, and Bloomberg where you remove ALL nodes that appear more than once from a sorted list. Learn the dummy-head predecessor skip pattern with Python and JavaScript, step-by-step dry run, and the critical difference from LC 83.