Given an array arr
of positive integers sorted in a strictly increasing order, and an integer k
.
Find the kth
positive integer that is missing from this array.
Example 1:
Input: arr = [2,3,4,7,11], k = 5 Output: 9 Explanation: The missing positive integers are [1,5,6,8,9,10,12,13,...]. The 5th missing positive integer is 9.
Example 2:
Input: arr = [1,2,3,4], k = 2 Output: 6 Explanation: The missing positive integers are [5,6,7,...]. The 2nd missing positive integer is 6.
Constraints:
1 <= arr.length <= 1000
1 <= arr[i] <= 1000
1 <= k <= 1000
arr[i] < arr[j]
for1 <= i < j <= arr.length
class Solution { public int findKthPositive(int[] arr, int k) { int n = arr.length; int end = k + arr[n - 1]; List<Integer> list = new ArrayList(); for(int i : arr) list.add(i); int res = -1; for(int i = 1; i <= end; i++) { if(list.indexOf(i) < 0) k--; if(k == 0) { res = i; break; } } return res; } }