Kth Missing Positive Number
Given an array arr of positive integers sorted in a strictly increasing order, and an integer k.
Return the k^th positive integer that is missing from this array.
Follow up: Could you solve this problem in less than O(n) complexity?
Example 1
Input
arr = [2,3,4,7,11], k = 5Output
9The missing positive integers are [1, 5, 6, 8, 9, 10, 12, 13, ...], so the 5^th missing positive integer is 9.
Example 2
Input
arr = [1,2,3,4], k = 2Output
6The missing positive integers are [5, 6, 7, ...], so the 2^nd missing positive integer is 6.
Constraints
- 1 <= arr.length <= 1000
- 1 <= arr[i] <= 1000
- 1 <= k <= 1000
- arr[i] < arr[j] for 1 <= i < j <= arr.length