3911. K-th Smallest Remaining Even Integer in Subarray Queries

Hard27.0% Acceptance

You are given an integer array nums where nums is strictly increasing.

You are also given a 2D integer array queries, where queries[i] = [l_i, r_i, k_i].

For each query [l_i, r_i, k_i]:

Consider the subarray nums[l_i..r_i]
From the infinite sequence of all positive even integers: 2, 4, 6, 8, 10, 12, 14, ...
Remove all elements that appear in the subarray nums[l_i..r_i].
Find the k_i^th smallest integer remaining in the sequence after the removals.

Return an integer array ans, where ans[i] is the result for the i^th query.

Example 1:

Input: nums = [1,4,7], queries = [[0,2,1],[1,1,2],[0,0,3]]

Output: [2,6,6]

Explanation:

`i`	`queries[i]`	`nums[l_i..r_i]`	Removed Evens	Remaining Evens	`k_i`	`ans[i]`
0	[0, 2, 1]	[1, 4, 7]	[4]	2, 6, 8, ...	1	2
1	[1, 1, 2]	[4]	[4]	2, 6, 8, ...	2	6
2	[0, 0, 3]	[1]	[]	2, 4, 6, ...	3	6

Thus, ans = [2, 6, 6].

Example 2:

Input: nums = [2,5,8], queries = [[0,1,2],[1,2,1],[0,2,4]]

Output: [6,2,12]

Explanation:

`i`	`queries[i]`	`nums[l_i..r_i]`	Removed Evens	Remaining Evens	`k_i`	`ans[i]`
0	[0, 1, 2]	[2, 5]	[2]	4, 6, 8, ...	2	6
1	[1, 2, 1]	[5, 8]	[8]	2, 4, 6, ...	1	2
2	[0, 2, 4]	[2, 5, 8]	[2, 8]	4, 6, 10, 12, ...	4	12

Thus, ans = [6, 2, 12].

Example 3:

Input: nums = [3,6], queries = [[0,1,1],[1,1,3]]

Output: [2,8]

Explanation:

`i`	`queries[i]`	`nums[l_i..r_i]`	Removed Evens	Remaining Evens	`k_i`	`ans[i]`
0	[0, 1, 1]	[3, 6]	[6]	2, 4, 8, ...	1	2
1	[1, 1, 3]	[6]	[6]	2, 4, 8, ...	3	8

Thus, ans = [2, 8].

Constraints: