1283 Find the Smallest Divisor Given a Threshold

class Solution 
{

     public static int sumByD(int[] arr, int div) 
     {
        int n = arr.length; 
        
        //Find the summation of division values:
        int sum = 0;
        for (int i = 0; i < n; i++)
         {
            sum += Math.ceil((double)(arr[i]) / (double)(div));
        }
        return sum;
    }


    public int smallestDivisor(int[] arr, int threshold) 
    {
       int n = arr.length; 

        if(n > threshold) 
        return -1;

        //Find the maximum element:
        int maxi = Integer.MIN_VALUE;
        for (int i = 0; i < n; i++) 
        {
            maxi = Math.max(maxi, arr[i]);
        }

        int low = 1, high = maxi;

        //Apply binary search:
        while (low <= high)
         {
            int mid = (low + high) / 2;
            if (sumByD(arr, mid) <= threshold)
             {
                high = mid - 1;
            }
             else
              {
                low = mid + 1;
            }
        }
        return low;
        
    }
}