Formatted question description: https://leetcode.ca/all/1060.html
1060. Missing Element in Sorted Array
Level
Medium
Description
Given a sorted array A
of unique numbers, find the Kth
missing number starting from the leftmost number of the array.
Example 1:
Input: A = [4,7,9,10], K = 1
Output: 5
Explanation:
The first missing number is 5.
Example 2:
Input: A = [4,7,9,10], K = 3
Output: 8
Explanation:
The missing numbers are [5,6,8,…], hence the third missing number is 8.
Example 3:
Input: A = [1,2,4], K = 3
Output: 6
Explanation:
The missing numbers are [3,5,6,7,…], hence the third missing number is 6.
Note:
1 <= A.length <= 50000
1 <= A[i] <= 1e7
1 <= K <= 1e8
Solution
If the array nums
is empty, simply return k
since all numbers are missing in nums
.
If k
is greater than or equal to the last number in nums
, then only the numbers in nums
are not missing and all the other numbers are missing, so the kth missing number is k + nums[0] + nums.length  1
.
Otherwise, starting from the first letter in nums
, check each number that is greater, and if a number is not in the array, then it is missing and decrease k
by 1. The process ends until the end of nums
is reached or k
becomes 0. Finally, return the current number plus k
.

class Solution { public int missingElement(int[] nums, int k) { if (nums == null  nums.length == 0) return k; int length = nums.length; if (k >= nums[length  1]) return k + nums[0] + length  1; int num = nums[0]; int index = 1; while (index < length && k > 0) { num++; if (num == nums[index]) index++; else k; } return num + k; } }

Todo

print("Todo!")