697. Degree of an Array-数组的度

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 in python:

class Solution:
    def findShortestSubArray(self, nums: List[int]) -> int:
        adict = dict()
        for item in nums:
            if item not in adict.keys():
                adict[item] = 1
            else:
                adict[item] += 1

        length = len(nums)
        degree = max(adict.values())
        alist = []
        for item in adict.keys():
            if adict[item] == degree:
                alist.append(item)

        result = float('inf')
        nums2 = nums[::-1]
        for item in alist:
            left = nums.index(item)
            right = nums2.index(item)
            temp = len(nums)-left-right
            if result > temp:
                result = temp
        return result