BinarySearch

//Write a program, that reads from the console an array of N integers and an integer K, sorts the array and using the
//method Array.BinSearch() finds the largest number in the array which is ≤ K.

using System;

namespace BinarySearch
{
    class BinarySearch
    {
        static void Main()
        {
            Console.WriteLine("Please enter n.");
            int n = Int32.Parse(Console.ReadLine());
            Console.WriteLine("Please enter k.");
            int k = Int32.Parse(Console.ReadLine());
            Console.WriteLine("Please enter integers for the array - each on a new line.");
            int[] integers = new int[n];

            for (int i = 0; i < n; i++)
            {
                Console.Write("integers [{0}] = ", i);
                integers[i] = Int32.Parse(Console.ReadLine());
                Console.WriteLine();
            }

            Array.Sort(integers);

            int index = Array.BinarySearch(integers, k);
            if (index > 0)
            {
                Console.WriteLine("K is at index {0}", index);
            }
            else if (Math.Abs(index) > integers.Length)
            {
                Console.WriteLine("K is not found. The biggest number in the array is {0} at index {1}.",
                                    integers[integers.Length-1], integers.Length - 1);
            }
            else if (Math.Abs(index) <= integers.Length)
            {
                index = ~index;
                Console.WriteLine("K is not found. The biggest number in the array not greater than k is {0}.",
                                    integers[index - 1]);
            }
        }
    }
}