You are given a string s consisting of lowercase English letters. Your task is to find the maximum difference diff = freq(a1) - freq(a2) between the frequency of characters a1 and a2 in the string such that: a1 has an odd frequency in the string. a

maxDifference.js

/**
 * @param {string} s
 * @return {number}
 */
var maxDifference = function(s) {
    // Step 1: Count frequencies of each character
    const freqMap = {}; // Object to store frequency of each character

    for (const char of s) {
        freqMap[char] = (freqMap[char] || 0) + 1; // Increment frequency count
    }

    // Step 2: Separate characters with odd and even frequencies
    let maxOdd = -Infinity; // Track the highest odd frequency
    let minEven = Infinity; // Track the lowest even frequency

    for (const [char, freq] of Object.entries(freqMap)) {
        if (freq % 2 === 1) { // Odd frequency
            maxOdd = Math.max(maxOdd, freq);
        } else {
            minEven = Math.min(minEven, freq);
        }
    }

    // Step 3: Compute the maximum difference
    return maxOdd === -Infinity || minEven === Infinity ? 0 : maxOdd - minEven;
};