Anagram Check (Frequency Count/Sort) — String Manipulation Patterns
The Anagram Check (Frequency Count/Sort) pattern applies when you need the Anagram Check (Frequency Count/Sort) technique within the String Manipulation Patterns pattern. Its time complexity is O(n log n) with sorting, O(n) with a hash map and space complexity O(1) to O(n). Common variations are Repeated Substring Pattern Detection and Palindrome Check (Two Pointers / Reverse).
Master anagram detection using frequency counting and sorting. Group anagrams efficiently.
Anagram Check (Frequency Count/Sort) 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 Anagram Check (Frequency Count/Sort) 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 valid anagram, group anagrams, anagram check, frequency count, leetcode 242, leetcode 49.
How to practise Anagram Check (Frequency Count/Sort) on Thita.ai
Read the theory for Anagram Check (Frequency Count/Sort), 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
- Palindrome Check (Two Pointers / Reverse) — Master palindrome checking using two pointers. Handle valid palindrome with alphanumeric and one removal cases.
- 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
Anagram Check (Frequency Count/Sort) 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.