242. Valid Anagram

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

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.

Approach

Solution

/**
 * @param {string} s
 * @param {string} t
 * @return {boolean}
 */
var isAnagram = function(s, t) {
  let freq = {};
  for (let c of s) freq[c] = (freq[c] || 0) + 1;
  
  for (let c of t) {
    if(!freq[c] || freq[c] === 0){
      return false;
    }
    freq[c] = freq[c] - 1;
  }
  return true;
};

Explanation