Valid Anagram — Practice

Problem

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

Examples

Example 1

Input: s = "anagram", t = "nagaram"

Output: true

Example 2

Input: s = "rat", t = "car"

Output: false

Constraints

•1 <= s.length, t.length <= 5*10^4
•s and t consist of lowercase English letters.

Hints

Hint 1

The brute force: sort both strings and compare them directly — anagrams become identical strings once sorted.

Hint 2

Sorting costs O(n log n) — can you determine anagram-ness without ever reordering anything?

Hint 3

Since both strings must contain the exact same characters the exact same number of times, a single frequency count (increment for one string, decrement for the other) answers the question in one pass.

Solutions

public boolean isAnagramSorting(String s, String t) {
    if (s.length() != t.length()) return false;
    char[] sChars = s.toCharArray();
    char[] tChars = t.toCharArray();
    Arrays.sort(sChars);
    Arrays.sort(tChars);
    return Arrays.equals(sChars, tChars);
}

Time: O(n log n) · Space: O(n) for the sorted copies