Check Whether Two Strings are Almost Equivalent

Two strings word1 and word2 are considered almost equivalent if the differences between the frequencies of each letter from 'a' to 'z' between word1 and word2 is at most 3.

Given two strings word1 and word2, each of length n, return true if word1 and word2 are almost equivalent*, or false otherwise*.

The frequency of a letter x is the number of times it occurs in the string.

LeetCode Problem - 2068

class Solution {
    public boolean checkAlmostEquivalent(String word1, String word2) {
        // Create a map to store the frequency differences of characters.
        Map<Character, Integer> frequencyMap = new HashMap<>();

        // Count frequencies for characters in word1
        for (char ch : word1.toCharArray()) {
            frequencyMap.put(ch, frequencyMap.getOrDefault(ch, 0) + 1);
            // Increment the count for the character in the map
        }

        // Subtract frequencies for characters in word2
        for (char ch : word2.toCharArray()) {
            frequencyMap.put(ch, frequencyMap.getOrDefault(ch, 0) - 1);
            // Decrement the count for the character in the map
        }

        // Check if the absolute difference for any character exceeds 3
        for (int freq : frequencyMap.values()) {
            if (Math.abs(freq) > 3) {
                // If the frequency difference is greater than 3, the words are not almost equivalent
                return false;
            }
        }

        // If no character's frequency difference exceeds 3, the words are almost equivalent
        return true;
    }
}