697. 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.

# @lc code=start
using LeetCode

function find_shortest_sub_array(nums::Vector{Int})
    mp = Dict{Int,Vector{Int}}()

    for (idx, num) in enumerate(nums)
        if num in keys(mp)
            mp[num][1] += 1
            mp[num][3] = idx
        else
            mp[num] = [1, idx, idx]
        end
    end
    maxn = minlen = 0
    for (cnt, l, r) in values(mp)
        if maxn < cnt
            maxn = cnt
            minlen = r - l + 1
        elseif maxn == cnt
            minlen = min(minlen, r - l + 1)
        end
    end
    minlen
end
# @lc code=end

find_shortest_sub_array (generic function with 1 method)

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