?
Solved

C# Problem Solving Execerscise

Posted on 2016-11-11
5
Medium Priority
?
76 Views
Last Modified: 2016-11-12
I have been trying to solve this problem https://www.hackerrank.com/challenges/repeated-string and i have tryed to many things but
i 'm stuck so can you help me solving it ?

the main problem here is i want the chars inside the s string to append on itself in a short duration and the size of the string = n and then calculate how many Char 'a' in the string

                       
string s = Console.ReadLine();
			long n = Convert.ToInt64(Console.ReadLine());
			while (s.Count() < n)
			{

			}
			var cont = s.Count(x => x == 'a');
			Console.WriteLine(cont);
			Console.ReadKey();

Open in new window

0
Comment
Question by:Omar Alaa
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 34

Expert Comment

by:it_saige
ID: 41884235
Programming is as much about solving the problem as it is about finding the most efficient solution.  I can tell you that the can be solved by calculating the results (which is more efficient) as opposed to creating the infinite string and then counting the characters.

-saige-
0
 
LVL 40

Expert Comment

by:Kyle Abrahams
ID: 41884248
Yeah, you'll definitely run into timeout errors.

I'm close in my solution but it still needs work:

//test 9;
 string s = "epsxyyflvrrrxzvnoenvpegvuonodjoxfwdmcvwctmekpsnamchznsoxaklzjgrqruyzavshfbmuhdwwmpbkwcuomqhiyvuztwvq";
            long n = 549382313570;

            long countA = 0;
            foreach (char c in s.ToCharArray())
            {
                if (c == 'a')
                    countA++;
            }


            long result = 0;

            if (countA > 0)
            {
                  //find out the amount of times A appears as a proportion.  
                   // so if test 1 is aba  and 10
                    // 2 / 3 == .66 * 10 = 6 times.
                result = (long)Math.Floor(((double)countA / s.Length) * n);

             //then process the leftovers.  
                for (int i = 0; i < (int) n % s.Length; i++)
                {
                    if (s[i] == 'a')
                        result++;
                }
            }
     Console.WriteLine(result);  // expected Result of 16481469408  

Open in new window

0
 
LVL 40

Accepted Solution

by:
Kyle Abrahams earned 1000 total points
ID: 41884255
Apparently there was a problem with my math.

SPOILER DON'T READ THIS CODE IF YOU DON'T WANT THE SOLUTION.

  long countA = 0;
            foreach (char c in s.ToCharArray())
            {
                if (c == 'a')
                    countA++;
            }


            long result = 0;

            if (countA > 0)
            {
                result = (long)Math.Floor((double)countA * (n / s.Length));

                for (int i = 0; i < (int) (n % s.Length); i++)
                {
                    if (s[i] == 'a')
                        result++;
                }
            }
          
             Console.WriteLine(result);

Open in new window

0
 
LVL 34

Assisted Solution

by:it_saige
it_saige earned 1000 total points
ID: 41884257
As Kyle let the cat out of the bag...  ;)

Here was my implementation (same spoiler as above):
using System;
using System.Linq;

namespace EE_Q28982570
{
	class Program
	{
		static void Main(string[] args)
		{
			string s = Console.ReadLine();
			long count, n = Convert.ToInt64(Console.ReadLine());

			if (string.IsNullOrEmpty(s) || n < 0)
				Console.WriteLine(0);

			count = (n / s.Length) * s.Count(c => c == 'a');
			for (int i = 0; i < n % s.Length; i++)
			{
				if (s[i] == 'a')
				{
					count++;
				}
			}
			Console.WriteLine(count);
			Console.ReadLine();
		}
	}
}

Open in new window


-saige-
0
 

Author Closing Comment

by:Omar Alaa
ID: 41884668
Thank you guys. and thank you for respecting the Spoil for answers . you were really helpful
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article is for Object-Oriented Programming (OOP) beginners. An Interface contains declarations of events, indexers, methods and/or properties. Any class which implements the Interface should provide the concrete implementation for each Inter…
Exception Handling is in the core of any application that is able to dignify its name. In this article, I'll guide you through the process of writing a DRY (Don't Repeat Yourself) Exception Handling mechanism, using Aspect Oriented Programming.
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…
Suggested Courses
Course of the Month10 days, 6 hours left to enroll

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question