EASY NC#2 Blind #53 Arrays & Hashing
242. Valid Anagram
📖 Problem
Given two strings s and t, return true if t is an anagram of s, and false otherwise. An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
🧠 Visual Learning Aid
1 Model the input into the right structure
2 Choose the core technique and invariant
3 Execute step-by-step with a sample
4 Validate complexity and edge cases
JS/TS Refreshers
- •Array methods (`push`, `pop`, `shift`, `slice`)
- •Object/Map/Set usage patterns
- •Function parameter and return typing
Logical Thinking Concepts
- •Define invariants before coding
- •Check edge cases first (`[]`, single element, duplicates)
- •Estimate time/space before implementation
💡 Approach
- → Anagrams have same character counts
- → Use frequency map to compare
- → Sort both strings and compare (alternative)
- → Time: O(n log n) for sort, O(n) for frequency map
- → Space: O(n) for frequency map, O(n) for sort
🛠️ Hints & Pitfalls
Hints
- •Anagrams have same character counts
- •Use frequency map to compare
- •Sort both strings and compare (alternative)
Common Pitfalls
- •Time: O(n log n) for sort, O(n) for frequency map
- •Space: O(n) for frequency map, O(n) for sort
🧪 Test Cases
Hidden tests on submit: 4
Test Case 1
Not run Input:
isAnagram('anagram', 'nagaram'); Expected:
true Test Case 2
Not run Input:
isAnagram('rat', 'car'); Expected:
false Test Case 3
Not run Input:
isAnagram('', ''); Expected:
true 📝 Code Editor
📤 Output