443. Find Kth Missing Positive Number

Given a sorted positive integer array arr and an integer k, return the k-th missing positive integer not present in arr.

Input: A sorted positive integer array arr and integer k.

Output: The k-th missing positive integer.

Examples

Input: [2,3,4,7,11], 5
Output: 9
Explanation: Missing positives: 1,5,6,8,9,... 5th missing is 9.

Input: [1,2,3,4], 2
Output: 6
Explanation: Missing: 5,6,7,... 2nd is 6.

Input: [5,6,7,8,9], 1
Output: 1
Explanation: 1st missing is 1.

Constraints

• 1 <= arr.length <= 10^3
• 1 <= arr[i] <= 10^3
• All distinct
• Sorted ascending
• 1 <= k <= 10^3

Asked by