using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication5
{

    class Search
    {
        public static int Seqsearch(int[] a, int item)
        {
            int loc;
            bool found = false;
            for (loc = 0; loc < a.Length; loc++)
                if (a[loc] == item)
                {
                    found = true;
                    break;
                }
            if (found)
                return loc;
            else
                return -1;
        }
        public static int Binarysearch(int[] a, int item,int left,int right)
        {
            
               int mid = (left + right) / 2;
               if (right < left)
                   return -1;
               else
                   if (a[mid] ==item)
                       return mid;
                   else
                       if (a[mid] > item)
                           return Binarysearch(a, item, left, mid - 1);
                           else
                           return Binarysearch(a, item, mid+1, right);



                        return -1;
        }
       



        static void Main(string[] args)
        {

            int[] a ={ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
            int key = Seqsearch(a, 4);
            Console.WriteLine(key);
            key = Binarysearch(a,6,0,9);
            Console.WriteLine(key);
        }
    }
}