Merging Two Sorted Lists — Linked List Manipulation Patterns
The Merging Two Sorted Lists pattern applies when you need the Merging Two Sorted Lists technique within the Linked List Manipulation Patterns pattern. Its time complexity is O(m + n) and space complexity O(1). It is used in 1 problem on Thita, including Merge Two Sorted Lists. Common variations are Reordering / Partitioning and In-place Reversal.
Learn to merge two sorted linked lists efficiently. Foundation for merge sort and k-way merge problems.
Merging Two Sorted Lists is one of the 5 subpatterns of the Linked List Manipulation Patterns pattern, which covers in-place reversal, merging sorted lists, reordering, and intersection detection. The whole pattern is about 2 hours of study. This subpattern is a core technique: expect it to come up directly in interviews.
What Merging Two Sorted Lists covers
Master linked list manipulation including in-place reversal, merging sorted lists, detecting intersections, and reordering. Essential pointer manipulation techniques for interviews. Problems in this subpattern are usually searched for as merge sorted lists, merge two lists, sorted list merge, linked list merge, leetcode 21.
How to practise Merging Two Sorted Lists on Thita.ai
Read the theory for Merging Two Sorted Lists, then work the problems attached to it in the browser editor. Your solution runs against the problem's test cases, and the AI coach offers a hint about the technique you are missing rather than a finished solution. Progress is tracked per subpattern, so the Linked List Manipulation Patterns tracker shows this one as covered once you have solved its problems.
Other subpatterns in Linked List Manipulation Patterns
- In-place Reversal — Master in-place linked list reversal including full reversal, partial reversal, and k-group reversal techniques.
- Reordering / Partitioning — Learn to reorder and partition linked lists. Master techniques like swap pairs, rotate list, and odd-even separation.
- Addition of Numbers — Master adding numbers represented as linked lists. Handle carry operations and different list lengths.
- Intersection Detection — Learn to find the intersection point of two linked lists using the two-pointer technique.
Related DSA patterns
- Binary Search Patterns — Standard binary search, rotated arrays, first/last occurrence, and search on answer space.
- Array/Matrix Manipulation Patterns — In-place operations, hashing, prefix sums, spiral traversal, and cyclic sort.
- Stack Patterns — Parentheses matching, monotonic stack, histogram, and expression evaluation.
- String Manipulation Patterns — Palindrome checking, anagram detection, pattern matching, and string conversion.
Where to go next
Merging Two Sorted Lists is one lesson in a 16-pattern DSA course. If you are preparing end to end, work the interview-critical patterns first and use the pattern sheet as the checklist; if you are here for one technique, the Linked List Manipulation Patterns guide is the shortest path back to the rest of it.