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.

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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 &gt;= x, but there are 2.
If x = 1, there should be 1 number &gt;= x, but there are 0.
If x = 2, there should be 2 numbers &gt;= 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.


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Constraints:


	1 &lt;= nums.length &lt;= 100
	0 &lt;= nums[i] &lt;= 1000


class Solution:
    def specialArray(self, nums: List[int]) -> int:
        nums.sort()
        for i in range(max(nums)+1):
            y=len(nums)-bisect.bisect_left(nums,i)
            if y==i:
                return i
        return -1

        
        
class Solution {
    public int specialArray(int[] nums) {
        int x = nums.length;
        int[] counts = new int[x+1];

        for(int elem : nums)
            if(elem >= x)
                counts[x]++;
            else
                counts[elem]++;

        int res = 0;
        for(int i = counts.length-1; i > 0; i--) {
            res += counts[i];
            if(res == i)
                return i;
        }

        return -1;
    }
}
class Solution {
public:
    int specialArray(vector<int>& nums) {
        int v[102];
        memset(v, 0, sizeof v);
        for (const auto &n : nums) {
            ++v[n > 100 ? 100 : n];
        }
        for (int i = 100; i > 0; --i) {
            v[i] = v[i + 1] + v[i];
            if (v[i] == i)
                return i;
        }
        return -1;
    }
};
var specialArray = function(nums) {
    const freq = new Array(1001).fill(0);
    for(let n of nums)
        freq[n]++;
    
    for(let i=1000, cnt=0; i>=0; i--){
        cnt += freq[i];
        if(i==cnt) return i;
    }
    
    return -1;
};
Special Array With X Elements Greater Than or Equal X