Hacker Rank - Priyanka and Toys

Little Priyanka visited a kids' shop. There are N toys and their weight is represented by an array W=[w1,w2,…,wN]. Each toy costs 1 unit, and if she buys a toy with weight w′, then she can get all other toys whose weight lies between [w′,w′+4] (both inclusive) free of cost.

Input Format

The first line contains an integer N i.e. number of toys.
Next line will contain N integers, w1,w2,…,wN, representing the weight array.

Output Format

Minimum units with which Priyanka could buy all of toys.

Solution C#

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

class Solution {

    static void Main(String[] args) {

        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */

         Int32 N = Convert.ToInt32(Console.ReadLine());//5;

            Int32[] w = Console.ReadLine().ToString().Split(' ').Select(n => Convert.ToInt32(n)).ToArray(); ; //{ 1, 2, 3, 17, 10 };

            Array.Sort(w);

            Int32 unit = 0; Int32 W = 0;

            for (int i = 0; i < w.Length; i++)

            {

                if (i == 0) { unit++; W = w[i]+4; }

                else

                {

                    if (w[i] > W) { unit++; W = w[i] + 4; }

                }

            }

            Console.WriteLine(unit);

    }

}