Advertising.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

//https://community.topcoder.com/stat?c=problem_statement&pm=7558


    public class AdvertisingAgency
    {
        static public void Main(string[] args)
        {
            int[] requests = new[]{100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
 100, 100, 100, 100, 100, 100, 100, 100, 100, 100
};
                
            int result = numberOfRejections(requests);
            Console.WriteLine("result: " + result);
            Console.ReadLine();
        }
        
        static public int numberOfRejections(int[] arrayOfRequests){
      
            int[] billboards = new int[101];
            int rejections = 0;
            
            
            foreach (var req in arrayOfRequests)
            {
                if(billboards[req] != 0)
                    rejections++;
                 else
                    billboards[req] = req;
                    
            }
            return rejections;        
        }
    }