2099. Find Subsequence of Length K With the Largest Sum

Description

You are given an integer array nums and an integer k. You want to find a subsequence of nums of length k that has the largest sum.

Returnany such subsequence as an integer array of length k.

A subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.

 

Example 1:

Input: nums = [2,1,3,3], k = 2
Output: [3,3]
Explanation:
The subsequence has the largest sum of 3 + 3 = 6.

Example 2:

Input: nums = [-1,-2,3,4], k = 3
Output: [-1,3,4]
Explanation: 
The subsequence has the largest sum of -1 + 3 + 4 = 6.

Example 3:

Input: nums = [3,4,3,3], k = 2
Output: [3,4]
Explanation:
The subsequence has the largest sum of 3 + 4 = 7. 
Another possible subsequence is [4, 3].

 

Constraints:

• 1 <= nums.length <= 1000
• -105 <= nums[i] <= 105
• 1 <= k <= nums.length

 

Solutions

Solution: Sorting

• Time complexity: O(nlogn)
• Space complexity: O(n)

 

JavaScript

/**
 * @param {number[]} nums
 * @param {number} k
 * @return {number[]}
 */
const maxSubsequence = function (nums, k) {
  const numsIndex = nums.map((num, index) => ({ num, index }));

  numsIndex.sort((a, b) => b.num - a.num);

  return numsIndex
    .slice(0, k)
    .sort((a, b) => a.index - b.index)
    .map(({ num }) => num);
};