integers into strings

integers into strings

[isaac_2004]

hi im new to ada and i want to take a number inputted from a user and
seperate the digits then arrange it in ascending and descending order
and subtract and ascending number from the descending number

for example

user inputs 7319

program outputs   9731 - 1379 = 8352

8532 - 2358 = 6174
 and so on


also loop it until number acquired after subtraction is the same as
starting number

like this
6174
7641 - 1467 = 6174  

what procedure would i use to do this

Re: integers into strings

[Jeffrey R. Carter]

isaac_2004@yahoo.com wrote:

> hi im new to ada and i want to take a number inputted from a user and
> seperate the digits then arrange it in ascending and descending order
> and subtract and ascending number from the descending number
> 
> for example
> 
> user inputs 7319
> 
> program outputs   9731 - 1379 = 8352

'Image converts a scalar into a String; 'Value works the other way.

Integer'Image (7319) = " 7319". Integer'Value ("9731") = 9731.

However, if you're getting the number from input, you could just input it as a 
String and skip the 1st step.

-- 
Jeff Carter
"My name is Jim, but most people call me ... Jim."
Blazing Saddles
39

Re: integers into strings

[isaac2004]

no im not converting the inputted number into a string im sorting the
digits of the value into ascending and descending order and then making
two different numbers out of it one ascending one descending

oh boys look what i found

hey where are the white women at

Blazing Saddles

Re: integers into strings

[Simon Wright]

"isaac2004" <isaac_2004@yahoo.com> writes:

> no im not converting the inputted number into a string im sorting
> the digits of the value into ascending and descending order and then
> making two different numbers out of it one ascending one descending

The input is a string.

A string is an array of characters, so if you can sort an array you
can sort a string. I don't know what the point of this exercise is for
you but some hints on how you might use attributes to help make a
function that sorts a string of arbitrary length are in this ..

   with Ada.Text_IO; use Ada.Text_IO;

   procedure Isaac is
      Input : constant String := "1234";
      Output : String (1 .. Input'Length);
   begin
      for I in Input'Range loop
         Output (Output'Last - (I - Input'First)) := Input (I);
      end loop;
      Put_Line (Output);
   end Isaac;

Once you have a string, you can convert it to an integer using
Integer'Value:

   Result : constant Integer := Integer'Value (Output);

Re: integers into strings

[Jeffrey R. Carter]

isaac2004 wrote:

> no im not converting the inputted number into a string im sorting the
> digits of the value into ascending and descending order and then making
> two different numbers out of it one ascending one descending

I suppose you could pull off the digits using "rem" and "/", sort those, and put 
them back together using "*" and "+", but it seems easier to deal with the 
numbers as Strings and the digits as Characters.

In any case, you're going to input the number as Characters. You may hide this 
by using something like Ada.Text_IO.Integer_IO, but the actual input is a 
sequence of characters, which is then interpreted as the image of a value of an 
integer type and converted to the corresponding value. That's why it's called 
"Text I/O". If you do decide to do the sorting with Characters, you can make 
things a little easier by simply inputting the number as a String.

-- 
Jeff Carter
"I would never want to belong to any club that
would have someone like me for a member."
Annie Hall
41