src/main/java/com/fishercoder/solutions/_1608.java

package com.fishercoder.solutions;

import java.util.Arrays;

public class _1608 {
    public static class Solution1 {
        public int specialArray(int[] nums) {
            Arrays.sort(nums);
            int max = nums[nums.length - 1];
            for (int x = 1; x <= max; x++) {
                int found = 0;
                int i = nums.length - 1;
                while (i >= 0 && nums[i] >= x) {
                    i--;
                    found++;
                }
                if (found == x) {
                    return x;
                }
            }
            return -1;
        }
    }
}