프로그래머스 level2 H-index(정렬)

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;

class Solution {
    
    public static int find(ArrayList<Integer> arr)
	{
		 int count=0;
		for(int i=arr.get((arr.size()-1)/2);i>0;i--)
		{
			count=0;
			for(int j=0;j<arr.size();j++)
			{
				if(arr.get(j)>=i)
					count++;
				else
					break;
			}
			if(count>=i)
				return i;
		}
		return 0;
	}
    
    public int solution(int[] citations) {
      ArrayList<Integer> arr = new ArrayList<>();
		for(int c:citations)
		{
			arr.add(c);
		}

		 Collections.sort(arr, Collections.reverseOrder());
		 int answer = find(arr);
        return answer;
    }
}