You are given an array nums of non-negative integers. nums is considered special if there exists a number x such that there are exactly x numbers in nums that are greater than or equal to x.
Notice that x does not have to be an element in nums.
Return x if the array is special, otherwise, return -1. It can be proven that if nums is special, the value for x is unique.
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.
Constraints:
1 <= nums.length <= 1000 <= nums[i] <= 1000class Solution {
public int specialArray(int[] nums) {
int n = nums.length;
Arrays.sort(nums);
if(n<=nums[0])
return n;
for(int i=1; i<n; i++){
int x = n-i;
if(x>nums[i-1] && x<=nums[i])
return x;
}
return -1;
}
}class Solution {
public int specialArray(int[] nums) {
int n = nums.length;
Arrays.sort(nums);
if(n<=nums[0])
return n;
for(int i=1; i<n; i++){
int x = n-i;
if(x>nums[i-1] && x<=nums[i])
return x;
}
return -1;
}
}