Palindrome Check (Two Pointers / Reverse) — String Manipulation Patterns
The Palindrome Check (Two Pointers / Reverse) pattern applies when you need the Palindrome Check (Two Pointers / Reverse) technique within the String Manipulation Patterns pattern. Its time complexity is O(n) and space complexity O(1). It is used in 3 problems on Thita, including Palindrome Number, Valid Palindrome and Valid Palindrome II. Common variations are Repeated Substring Pattern Detection and Anagram Check (Frequency Count/Sort).
Master palindrome checking using two pointers. Handle valid palindrome with alphanumeric and one removal cases.
Palindrome Check (Two Pointers / Reverse) is one of the 6 subpatterns of the String Manipulation Patterns pattern, which covers palindrome checking, anagram detection, pattern matching, and string conversion. The whole pattern is about 2 hours of study. This subpattern is a core technique: expect it to come up directly in interviews.
What Palindrome Check (Two Pointers / Reverse) covers
Master string manipulation including palindrome checking, anagram detection, string matching algorithms (KMP, Rabin-Karp), and conversion problems. Problems in this subpattern are usually searched for as palindrome check, valid palindrome, two pointer palindrome, leetcode 125, leetcode 680.
How to practise Palindrome Check (Two Pointers / Reverse) on Thita.ai
Read the theory for Palindrome Check (Two Pointers / Reverse), 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 String Manipulation Patterns tracker shows this one as covered once you have solved its problems.
Other subpatterns in String Manipulation Patterns
- Anagram Check (Frequency Count/Sort) — Master anagram detection using frequency counting and sorting. Group anagrams efficiently.
- Repeated Substring Pattern Detection — Learn to detect if a string can be constructed by repeating a substring pattern.
- Naive / KMP / Rabin-Karp — Master string matching algorithms including naive search, KMP pattern matching, and Rabin-Karp hashing.
- Integer and Roman Conversion — Learn to convert between integers and Roman numerals. Essential string manipulation problem.
- Multiply Strings (Manual Simulation) — Learn to multiply large numbers represented as strings using manual simulation of multiplication.
Related DSA patterns
- Linked List Manipulation Patterns — In-place reversal, merging sorted lists, reordering, and intersection detection.
- Stack Patterns — Parentheses matching, monotonic stack, histogram, and expression evaluation.
- Tree Traversal Patterns (DFS & BFS) — Preorder, inorder, level order traversal, LCA, and serialization.
- Heap (Priority Queue) Patterns — Top K elements, K-way merge, two heaps for median, and scheduling.
Where to go next
Palindrome Check (Two Pointers / Reverse) 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 String Manipulation Patterns guide is the shortest path back to the rest of it.