- Difficulty: Hard
- Tags: LeetCode, Hard, Greedy, Array, Hash Table, Sorting, Heap (Priority Queue), leetcode-2813, O(nlogk), O(k), Partial Sort, Heap, Quick Select, BST, Sorted List, Stack
Problem
You are given a 0-indexed 2D integer array items
of length n
and an integer k
.
items[i] = [profiti, categoryi]
, where profiti
and categoryi
denote the profit and category of the ith
item respectively.
Let's define the elegance of a subsequence of items
as total_profit + distinct_categories2
, where total_profit
is the sum of all profits in the subsequence, and distinct_categories
is the number of distinct categories from all the categories in the selected subsequence.
Your task is to find the maximum elegance from all subsequences of size k
in items
.
Return an integer denoting the maximum elegance of a subsequence of items
with size exactly k
.
Note: A subsequence of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the remaining elements' relative order.
Example 1:
Input: items = [[3,2],[5,1],[10,1]], k = 2 Output: 17 Explanation: In this example, we have to select a subsequence of size 2. We can select items[0] = [3,2] and items[2] = [10,1]. The total profit in this subsequence is 3 + 10 = 13, and the subsequence contains 2 distinct categories [2,1]. Hence, the elegance is 13 + 22 = 17, and we can show that it is the maximum achievable elegance.
Example 2:
Input: items = [[3,1],[3,1],[2,2],[5,3]], k = 3 Output: 19 Explanation: In this example, we have to select a subsequence of size 3. We can select items[0] = [3,1], items[2] = [2,2], and items[3] = [5,3]. The total profit in this subsequence is 3 + 2 + 5 = 10, and the subsequence contains 3 distinct categories [1,2,3]. Hence, the elegance is 10 + 32 = 19, and we can show that it is the maximum achievable elegance.
Example 3:
Input: items = [[1,1],[2,1],[3,1]], k = 3 Output: 7 Explanation: In this example, we have to select a subsequence of size 3. We should select all the items. The total profit will be 1 + 2 + 3 = 6, and the subsequence contains 1 distinct category [1]. Hence, the maximum elegance is 6 + 12 = 7.
Constraints:
1 <= items.length == n <= 105
items[i].length == 2
items[i][0] == profiti
items[i][1] == categoryi
1 <= profiti <= 109
1 <= categoryi <= n
1 <= k <= n