242. Valid Anagram

Problem

Tags: Hash Table, String, Sorting

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.

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.

Follow up: What if the inputs contain Unicode characters? How would you adapt your solution to such a case?

Code

JS

// 242. Valid Anagram (4/14/53726)
// Runtime: 88 ms (75.26%) Memory: 39.59 MB (93.89%) 

/**
 * @param {string} s
 * @param {string} t
 * @return {boolean}
 */
function isAnagram(s, t) {
    if (s.length !== t.length) return false;
    const map = {};
    for (let i = 0; i < t.length; i++) map[t[i]] = (map[t[i]] || 0) + 1;

    for (let i = 0; i < s.length; i++) {
        if (!map[s[i]]) return false;
        map[s[i]]--;
    }
    return true;
}