recursion

yui0329 · April 23rd, 2005, 09:40 AM

Modify the following code, rewrite the "CountWord()", use recursion.

using System;

public class StringUse
{

public static void Main()
{
string lines = "";
string[] words = {"the", "they", "them", "there"};
Console.WriteLine("Read 2 lines");

for (int i = 0; i < 2; ++i)
lines = string.Concat(lines, Console.ReadLine() + "\n");

lines = lines.ToLower();

Console.WriteLine("Read 2 lines");
Console.WriteLine("Echo 2 lines" + "\n" + lines);

for (int i = 0; i < words.Length; ++i)
Console.WriteLine(words[i] + " appears "
+ CountWords(lines, words[i]) + " times");
}

public static int CountWords(string s, string word)
{
string temp = s;
int i = s.IndexOf(word);
int count = 0;
while (i < temp.Length && i != -1)
{
Console.WriteLine("in while " + i);
++count;
temp = temp.Substring(i + word.Length,
temp.Length -i - word.Length);
i = temp.IndexOf(word);
}
return count;
}
}

Imar · April 24th, 2005, 02:58 AM

What's this? Are you sharing useful code, or do you want us to do your homework?

Imar
---------------------------------------
Imar Spaanjaars
Everyone is unique, except for me.

yui0329 · April 24th, 2005, 06:42 AM

Please help me, I don`t understand how to do the recursion.

Imar · April 24th, 2005, 07:00 AM

Quote:

quote:do you want us to do your homework?

Do you?

Imar
---------------------------------------
Imar Spaanjaars
Everyone is unique, except for me.
While typing this post, I was listening to: Everybody's Changing by Keane (Track 5 from the album: Hopes and Fears) What's This?

mehdi62b · April 24th, 2005, 02:02 PM

in recursion problems you should just find a recursion relation in your problem also you should have an initial check for stopping the recursion

Code:

        public static int RecursiveCountWords(string s,string word)
        {
            int index=-1;
            if (s==string.Empty) return 0;
            index=s.IndexOf(word);
            if(index!=-1) 
                s=s.Remove(index,word.Length);
            else 
                return 0;
            return 1+CountWordsRecursion(s,word);
        }

get the idea?

_____________
Mehdi.
software student.

yui0329 · April 24th, 2005, 09:04 PM

Yes, I got the idea, thank you very much!!

Hal Levy · April 28th, 2005, 09:36 AM

Mehdi- good job on his homework.

Hal Levy
I am here to help you, not do it for you.
That is, unless you hire me. I am looking for work.