Return the value that appears most often in nums. If several values are tied for the highest count, return the smallest of them. Return None for an empty list.
Examples
Input: nums = [4, 1, 4, 1, 7]
Output: 1
Explanation: 4 and 1 both appear twice; 1 is smaller.
Input: nums = [3, 3, 2]
Output: 3
Constraints
0 <= len(nums) <= 10**5- Target complexity: O(n) time.
Goals
- Find the maximum of a frequency table
- Apply an explicit tie-breaking rule