Friday Programming Quiz [modified]

Rama Krishna Vavilala

There are some number of text files. Each file contains a number separated by a comma and a name. e.g. File 1

1,Chris Maunder
20248,Nishant Sivakumar
36803,Marc Clifton
...

File 2

6556,Christian Graus
7741,John Simmons / outlaw programmer
15383,Rama Krishna Vavilala
...

All the records in the file are sorted by the id (the number). Note there can be many such files. The purpose is to generate a new file like this:

1,Chris Maunder
6556,Christian Graus
7741,John Simmons / outlaw programmer
15383,Rama Krishna Vavilala
20248,Nishant Sivakumar
36803,Marc Clifton
...

Of course it can be done in a programming language of your choice. I might be able to hand over a prize for the most innovative and interesting/ solution.;) -- modified at 15:01 Friday 24th August, 2007

Co-Author ASP.NET AJAX in Action

PIEBALDconsult

type *.in | sort > CP.out Unless, by "(the number)", you mean "the numerical value of the id".

Jim Crafton

"Computer" I shout. "Yes Master?" "Create a file for me!" "All right. What do you want in the file?" "Names, and an ID number. Can you do that brainiac?" "Cut the crap Boss. Sure thing. Anything else?" "Yeah, keep the file sorted by ID, in ascending order." "Fine. Done. Where do I get the names from?" "They are in another file, it's text, and comma delimited. The first thing on a line is a number, the ID, followed by a name." "Are there multiple entries in a file?" "Yep." "OK, ready to rock and roll."

¡El diablo está en mis pantalones! ¡Mire, mire! Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)! SELECT * FROM User WHERE Clue > 0 0 rows returned Save an Orange - Use the VCF! VCF Blog

Rama Krishna Vavilala

I expected that someone will come with this kind of solution.;)

PIEBALDconsult wrote:

"the numerical value of the id.

Yes.

Co-Author ASP.NET AJAX in Action

Rama Krishna Vavilala

Is it a variation of Osmo's Plain English.

Co-Author ASP.NET AJAX in Action

Jim Crafton

No, but I realized after a few lines that's what it might look like. :)

¡El diablo está en mis pantalones! ¡Mire, mire! Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)! SELECT * FROM User WHERE Clue > 0 0 rows returned Save an Orange - Use the VCF! VCF Blog

Chris Meech

Rama Krishna Vavilala wrote:

Of course it can be done in language of your choice

Give a couple of hours and I'll have the COBOL version slapped together for you. :)

Chris Meech I am Canadian. [heard in a local bar]

Rama Krishna Vavilala

You have all the time:)

Co-Author ASP.NET AJAX in Action

Luis Alonso Ramos

In English.NET? :)

create a new List and Hashtable
 
foreach file
{
   open file
 
   while(i can read from file)
   {
      read a line
      split it by the comma
      add the id to the list
      add the id and name to the hashtable (key, value)
   }
 
   close file
}
 
list.Sort();
 
open result file
 
foreach id in the list
{
   get the name from the hashtable using the id
   write to file(String.Format("{0},{1}", id, name);
}
 
close result file

:)

Luis Alonso Ramos Intelectix Chihuahua, Mexico

My Blog!

El Corazon

Rama Krishna Vavilala wrote:

Of course it can be done in language of your choice.

too lazy to write you code.... but I had this laying in my bookmarks. how about a bitonic merge sort on the GPU.... http://www.cis.upenn.edu/~suvenkat/700/lectures/19/sorting-kider.pdf[^]

_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

ToddHileHoffer

I wrote an application to do this. Front end and all in 7 minutes. I could have used a hash-table or arraylist or whatever but I used ado.net because that's the kind of guy I am. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace WindowsApplication1 { public partial class Form1 : Form { DataTable dt; Int32 FilesRead = 0; private void AddFileToDataTable(System.IO.Stream fileStream) { System.IO.StreamReader sr = new System.IO.StreamReader(fileStream); string input; DataRow dr; while ((input = sr.ReadLine()) != null) { string[] s = input.Split(new char[] { ',' }); dr = dt.NewRow(); dr["ID"] = int.Parse(s[0]); dr["Name"] = s[1]; dt.Rows.Add(dr); } sr.Close(); } public Form1() { InitializeComponent(); dt = new DataTable(); DataColumn dc; dc = new DataColumn(); dc.DataType = System.Type.GetType("System.Int32"); dc.ColumnName = "ID"; dt.Columns.Add(dc); dc = new DataColumn(); dc.DataType = System.Type.GetType("System.String"); dc.ColumnName = "Name"; dt.Columns.Add(dc); } private void button1_Click(object sender, EventArgs e) { this.openFileDialog1.ShowDialog(); System.IO.Stream sr = System.IO.File.Open(this.openFileDialog1.FileName, System.IO.FileMode.Open); AddFileToDataTable(sr); FilesRead += 1; this.label1.Text = "Files Read:" + FilesRead.ToString(); } private void button2_Click(object sender, EventArgs e) { this.saveFileDialog1.ShowDialog(); DataView dv = new DataView(dt); dv.Sort = "ID ASC"; dt = dv.ToTable(); StringBuilder sb = new StringBuilder(); foreach (DataRow r in dt.Rows) { sb.Append(r[0].ToString() + "," + r[1].ToString() + Environment.NewLine); } System.IO.File.WriteAllText(this.saveFileDialog1.FileName, sb.ToString()); } } }

<

Daniel Grunwald

using System.Linq;
class Program {
public static void Main(string[] args) {
args.Select(
fileName => System.IO.File.ReadAllLines(fileName).Select(
line => new { ID = int.Parse(line.Split(',')[0]), Name = line.Split(',')[1]}
))
.Aggregate((a, b)=>a.Concat(b))
.OrderBy(a=>a.ID).ToList().ForEach(a=>System.Console.WriteLine("{0},{1}", a.ID, a.Name));
}
}

If you require that the output is written to a file, use this:

	System.IO.File.WriteAllLines("output.txt", args.Select(
		fileName => System.IO.File.ReadAllLines(fileName).Select(
			line => new { ID = int.Parse(line.Split(',')\[0\]), Name = line.Split(',')\[1\]}
		))
		.Aggregate((a, b)=>a.Concat(b))
		.OrderBy(a=>a.ID).Select(a=>string.Format("{0},{1}", a.ID, a.Name)).ToArray());

Last modified: 8mins after originally posted --

PIEBALDconsult

What about duplicates?

Chris Losinger

this one feels too much like actual work

image processing toolkits | batch image processing

Rama Krishna Vavilala

There are no duplicates. Assume unique values

Co-Author ASP.NET AJAX in Action

Minosknight

00110001001011000100001101101000011100100110100101110011001000000 10011010110000101110101011011100110010001100101011100100000110100 00101000110110001101010011010100110110001011000100001101101000011 10010011010010111001101110100011010010110000101101110001000000100 01110111001001100001011101010111001100001101000010100011011100110 11100110100001100010010110001001010011011110110100001101110001000 00010100110110100101101101011011010110111101101110011100110010000 00010111100100000011011110111010101110100011011000110000101110111 00100000011100000111001001101111011001110111001001100001011011010 11011010110010101110010000011010000101000110001001101010011001100 11100000110011001011000101001001100001011011010110000100100000010 01011011100100110100101110011011010000110111001100001001000000101 01100110000101110110011010010110110001100001011011000110000100001 10100001010001100100011000000110010001101000011100000101100010011 10011010010111001101101000011000010110111001110100001000000101001 10110100101110110011000010110101101110101011011010110000101110010 00001101000010100011001100110110001110000011000000110011001011000 10011010110000101110010011000110010000001000011011011000110100101 100110011101000110111101101110

Think of it this way...using a Stradivarius violin to pound nails should not be considered a sound construction technique

Luis Alonso Ramos

Can anyone do this help me do this for my homework? It's due in two hours and I've had all the semester!! Please help urgent!! ;P

Luis Alonso Ramos Intelectix Chihuahua, Mexico

My Blog!

PIEBALDconsult

Rama Krishna Vavilala wrote:

Assume

That's a naughty word.

Daniel Grunwald

Rama Krishna Vavilala wrote:

No duplicates!

Does this mean the input files do not contain duplicates, or duplicates need to be removed? In my solution, put a ".Distinct()" between the Aggregate line and the Sort+Output line if you need to remove duplicates.

Rama Krishna Vavilala

Yes! It is close. All the quizzes are based on actual work I did. It is based on a IIS log analyzer utility I once wrote which sorted log records from different servers into one file. Except that the actual program was far more complex as it had to read large files in buffers and merge them.

Co-Author ASP.NET AJAX in Action