Degree of an Array

Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.

Your task is to find the smallest possible length of a (contiguous) subarray of nums, that has the same degree as nums.

 

Example 1:

Input: nums = [1,2,2,3,1]
Output: 2
Explanation: 
The input array has a degree of 2 because both elements 1 and 2 appear twice.
Of the subarrays that have the same degree:
[1, 2, 2, 3, 1], [1, 2, 2, 3], [2, 2, 3, 1], [1, 2, 2], [2, 2, 3], [2, 2]
The shortest length is 2. So return 2.

Example 2:

Input: nums = [1,2,2,3,1,4,2]
Output: 6
Explanation: 
The degree is 3 because the element 2 is repeated 3 times.
So [2,2,3,1,4,2] is the shortest subarray, therefore returning 6.

 

Constraints:

  • nums.length will be between 1 and 50,000.
  • nums[i] will be an integer between 0 and 49,999.
SOLUTION:
from collections import defaultdict

class Solution:
    def findShortestSubArray(self, nums: List[int]) -> int:
        pos = {}
        ctr = defaultdict(int)
        for i, el in enumerate(nums):
            ctr[el] += 1
            if el in pos:
                pos[el][1] = i
            else:
                pos[el] = [i, i]
        deg = max(ctr.values())
        return min(p[1] - p[0] + 1 for el, p in pos.items() if ctr[el] == deg)

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