Anagram (DSA)

 

Problem Statement:(👈click here for GFG)

Given two strings a and b consisting of lowercase characters. The task is to check whether two given strings are an anagram of each other or not. An anagram of a string is another string that contains the same characters, only the order of characters can be different. For example, act and tac are an anagram of each other.

Note:-

• If the strings are anagrams you have to return True or else return False

• |s| represents the length of string s.

Example 1:

Input:a = geeksforgeeks, b = forgeeksgeeks
Output: YES
Explanation: Both the string have same characters with
        same frequency. So, both are anagrams.

Example 2:

Input:a = allergy, b = allergic
Output: NO
Explanation: Characters in both the strings are 
        not same, so they are not anagrams.

Your Task:
You don't need to read input or print anything. Your task is to complete the function isAnagram() which takes the string a and string b as input parameter and check if the two strings are an anagram of each other. The function returns true if the strings are anagram else it returns false.

Expected Time Complexity:O(|a|+|b|).
Expected Auxiliary Space: O(Number of distinct characters).

Constraints:
1 ≤ |a|,|b| ≤ 10^5

Solution:

class Solution {
    isAnagram(a, b) {
        if (a.length !== b.length) {
            return false;
        }
        
        const freq = new Array(26).fill(0);
        
        for (let i = 0; i < a.length; i++) {
            freq[a.charCodeAt(i) - 'a'.charCodeAt(0)]++;
        }
        
        for (let i = 0; i < b.length; i++) {
            freq[b.charCodeAt(i) - 'a'.charCodeAt(0)]--;
            if (freq[b.charCodeAt(i) - 'a'.charCodeAt(0)] < 0) {
                return false;
            }
        }
      return true;
    }
}