LeetCode in Elixir
215. Kth Largest Element in an Array
Medium
Given an integer array nums and an integer k, return the kth largest element in the array.
Note that it is the kth largest element in the sorted order, not the kth distinct element.
You must solve it in O(n) time complexity.
Example 1:
Input: nums = [3,2,1,5,6,4], k = 2
Output: 5
Example 2:
Input: nums = [3,2,3,1,2,4,5,5,6], k = 4
Output: 4
Constraints:
1 <= k <= nums.length <= 105-104 <= nums[i] <= 104
Solution
defmodule Solution do
@spec find_kth_largest(nums :: [integer], k :: integer) :: integer
def find_kth_largest(nums, k) do
nums
|> Enum.with_index()
|> Enum.reduce(:gb_sets.new(), fn {n, i}, q ->
cond do
:gb_sets.is_member({n,i}, q) ->
q
:gb_sets.size(q) < k ->
:gb_sets.insert({n,i}, q)
true ->
{smol, qq} = :gb_sets.take_smallest(q)
:gb_sets.insert(max(smol, {n,i}), qq)
end
end)
|> :gb_sets.smallest()
|> elem(0)
end
end