1function specialArray(nums) {
2    nums.sort((a, b) => a - b);
3    for (let x = 0; x <= nums.length; x++) {
4        let count = nums.filter(num => num >= x).length;
5        if (count === x) {
6            return x;
7        }
8    }
9    return -1;
10}
11
12const nums = [0, 4, 3, 0, 4];
13console.log(specialArray(nums));

1using System.Linq;

class SpecialArray {
    private int CountGreaterEqual(int[] nums, int target) {
        return nums.Count(num => num >= target);
    }

    public int SpecialArrayFunc(int[] nums) {
        Array.Sort(nums);
        int left = 0, right = nums.Length;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            int count = CountGreaterEqual(nums, mid);
            if (count == mid) {
                return mid;
            } else if (count < mid) {
                right = mid - 1;
            } else {
                left = mid + 1;
            }
        }
        return -1;
    }

    static void Main() {
        SpecialArray sa = new SpecialArray();
        int[] nums = {0, 4, 3, 0, 4};
        Console.WriteLine(sa.SpecialArrayFunc(nums));
    }
}