Java Help - Please Help!

Author

Please Help!

the_real_g

2004-10-22, 8:56 am

Hey guys i really need some help. I'm trying to make a program that takes a
string as input e.g "AAABBCCD" and outputs a histogram of this e.g.
A ***
B **
C **
D *
I have this program (below) that simply lists the elements of the string
but doesn't produce the histogram. Does anyone have some code that
finishes it off? I've been trying for ages!
Thanks alot!

import java.io.*;

class Histogram
{
public static void main(String[] args) throws java.io.IOException
{
char c;
BufferedReader br = new BufferedReader(new
InputStreamReader(System.in));
String name = null;

System.out.println("Please input a string and press enter:");
try {
name = br.readLine();
} catch (IOException ioe) {
System.out.println("IO error trying to read your name!");
System.exit(1);
}

//change string to uppercase
name = name.toUpperCase();

for(int i = 0; i < name.length() ; i++ )
{
/*
This for loop would go through each letter in the string.
Everytime you encounter a letter see if you've
already seen the letter or not and keep count of each letter
you have encountered.
*/
//Just default output to show for loops is functional
System.out.println(""+name.charAt(i));
}
}
}

Gordon Beaton

2004-10-22, 8:56 am

On Fri, 22 Oct 2004 07:15:29 -0400, the_real_g wrote:
> I have this program (below) that simply lists the elements of the
> string but doesn't produce the histogram. Does anyone have some code
> that finishes it off? I've been trying for ages!

Show us some of your failed attempts!

It looks like the only code "you" have managed to produce, is the
template your instructor gave you to get you started.

/gordon

--
[ do not email me copies of your followups ]
g o r d o n + n e w s @ b a l d e r 1 3 . s e

Boudewijn Dijkstra

2004-10-22, 8:56 am

"the_real_g" <gregriddle84@hotmail.com> schreef in bericht
news:19e7bca86b375052219c7648b3bcc057@lo
calhost.talkaboutprogramming.com...
> Hey guys i really need some help. I'm trying to make a program that
> takes a string as input e.g "AAABBCCD" and outputs a histogram of this
> e.g.
> A ***
> B **
> C **
> D *
> I have this program (below) that simply lists the elements of the
> string but doesn't produce the histogram. Does anyone have some code
> that finishes it off? I've been trying for ages!
> Thanks alot!

Try (for yourself) to (re)formulate an algorithm using programming terms, e.g.
numbers, datastructures and operations on them. Then test its correctness by
going over the algorithm with different inputs. Finally, implement the
algorithm in a computer program.

Paul Lutus

2004-10-22, 3:58 pm

the_real_g wrote:

> Hey guys i really need some help. I'm trying to make a program that takes
> a string as input e.g "AAABBCCD" and outputs a histogram of this e.g.
> A ***
> B **
> C **
> D *
> I have this program (below) that simply lists the elements of the string
> but doesn't produce the histogram. Does anyone have some code that
> finishes it off?

"Finishes it off"? Your code doesn't do anything that the assignment
requires.

Rule number one: Stop asking for code.

1. Think about how the program works. What does it have to do, when, with
whst results?

2. Read your Java computer programming textbook from cover to cover.

3. Write your program.

--
Paul Lutus
http://www.arachnoid.com

Tor Iver Wilhelmsen

2004-10-22, 8:57 pm

"the_real_g" <gregriddle84@hotmail.com> writes:

> /*
> This for loop would go through each letter in the string.
> Everytime you encounter a letter see if you've
> already seen the letter or not and keep count of each letter
> you have encountered.
> */

We don't exist to do your homework, but a couple of hints:

*) If you know you only will get letters, use char-'A' as offset in an
int array which counts occurences
*) Use i+'A' as the "label" afterwards.

Aki \Sus\ Laukkanen

2004-10-25, 3:59 am

Paul Lutus wrote:

<snip request for making the_real_g's homework for him>

> 1. Think about how the program works. What does it have to do, when, with
> whst results?

And this, I would stress, is the really, really important part.
The motto "Divide and conquer" is the programmer's best friend.
After you know *what* you want done, it's easy to break it down to a set
of sub-operations (1. do A, 2. do B, 3. do C) and then (with the help of
a textbook) write the code you need to get A, B and C done.

> 2. Read your Java computer programming textbook from cover to cover.
>
> 3. Write your program.

IMHO, it is not necessary to read the textbook from cover to cover
before beginning to write the program. What I would do (and, in some
cases, still do) is start with point 1, then start implementing the
elemants necessary and use the textbook as reference where needed.

--
-Aki "Sus" Laukkanen

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