#1608
Special Array With X Elements Greater Than or Equal X
pupil · 335 · lc easy +22 · verified · 66.8% accepted · 2,338 likes · top 72%
Description
Given an array nums of non-negative integers, determine if there exists a value x such that exactly x elements in nums are greater than or equal to x. Note that x does not need to appear in nums. Return x if it exists, otherwise return -1. Such a value is guaranteed to be unique when it exists.
Example 1:
Input: nums = [3,5]
Output: 2
Explanation: There are 2 values (3 and 5) that are greater than or equal to 2.
Example 2:
Input: nums = [0,0]
Output: -1
Explanation: No numbers fit the criteria for x.
If x = 0, there should be 0 numbers >= x, but there are 2.
If x = 1, there should be 1 number >= x, but there are 0.
If x = 2, there should be 2 numbers >= x, but there are 0.
x cannot be greater since there are only 2 numbers in nums.
Example 3:
Input: nums = [0,4,3,0,4]
Output: 3
Explanation: There are 3 values that are greater than or equal to 3.
Code
1
2
3