花花酱 LeetCode 3005. Count Elements With Maximum Frequency

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

Solution: Hashtable

Use a hashtable to store the frequency of each element, and compare it with a running maximum frequency. Reset answer if current frequency is greater than maximum frequency. Increment the answer if current frequency is equal to the maximum frequency.

Time complexity: O(n)
Space complexity: O(n)