CountElementsWithMaximumFrequency.ts

// Source : https://leetcode.com/problems/count-elements-with-maximum-frequency/
// Author : francisco
// Date   : 2024-01-14

/*****************************************************************************************************
 *
 * You are given an array nums consisting of positive integers.
 *
 * Return the total frequencies of elements in nums such that those elements all have the maximum
 * frequency.
 *
 * The frequency of an element is the number of occurrences of that element in the array.
 *
 * Example 1:
 *
 * Input: nums = [1,2,2,3,1,4]
 * Output: 4
 * Explanation: The elements 1 and 2 have a frequency of 2 which is the maximum frequency in the array.
 * So the number of elements in the array with maximum frequency is 4.
 *
 * Example 2:
 *
 * Input: nums = [1,2,3,4,5]
 * Output: 5
 * Explanation: All elements of the array have a frequency of 1 which is the maximum.
 * So the number of elements in the array with maximum frequency is 5.
 *
 * Constraints:
 *
 * 	1 <= nums.length <= 100
 * 	1 <= nums[i] <= 100
 ******************************************************************************************************/

/**
 * @param {number[]} nums
 * @returns {number}
 * return the total frequencies of elements in nums such that those elements have the maximum frequency

 * Time Complexity: O(n)
 * Space Complexity: O(n)
 */
export function maxFrequencyElements(nums: number[]): number {
  const freq: Record<number, number> = {};
  let max: number = 0;

  for (const num of nums) {
    const val: number = (freq[num] ?? 0) + 1;
    freq[num] = val;
    if (val > max) max = val;
  }

  return Object.values(freq).reduce((acc: number, crr: number) => {
    if (crr === max) return acc + crr;
    return acc;
  }, 0);
}