How to check if letters are in a string?

How to check if letters are in a string?

[Trish Cayetano]

Hi, 

How do you check if (exact number of) letters are in a string? 

1. This example should PASS because every letter is found in the string
LETTERS: HID
STRING:  HIDDEN

2. This example should FAIL because the letters contain 2 N's but the string only has 1 N. 
LETTERS: NINE
STRING:  HIDDEN


Pangram doesn't seem to be a solution... because it considers #2 above as PASS.
This is because pangrams check for AT LEAST one letter (this means, it considers a pangram even if the letter is a duplicate)


Is there another way how to check if (exact number of) letters are in a string? 
Thank you very much!


====
Here is the sample code: 

with Ada.Text_IO; use Ada.Text_IO;
with Ada.Strings.Maps; use Ada.Strings.Maps;
with Ada.Characters.Handling; use Ada.Characters.Handling;
procedure main is
 
	function ispangram(txt: String) return Boolean is
		lowtxt : String := To_Lower(txt);
		letset,txtset : Character_Set;
		begin
		letset := To_Set("nine");
		txtset := To_Set(lowtxt);
		return (letset-txtset)=Null_Set;
	end ispangram;
 
begin
put_line(Boolean'Image(ispangram("hidden")));

end main;

============================================
OUTPUT: 

C:\Users\a0284014\Desktop\ada\pangram\obj\main
TRUE

[2015-07-18 16:52:42] process terminated successfully, elapsed time: 00.37s

Re: How to check if letters are in a string?

[Nasser M. Abbasi]

On 7/18/2015 4:00 AM, Trish Cayetano wrote:
> Hi,
>
> How do you check if (exact number of) letters are in a string?
>
> 1. This example should PASS because every letter is found in the string
> LETTERS: HID
> STRING:  HIDDEN
>

I do not follow. The 'D' in 'letters' occur 1 time but it occurs
2 times in 'string'. So this is not the _exact number_ of
letters in the string.

> 2. This example should FAIL because the letters contain 2 N's but the string only has 1 N.
> LETTERS: NINE
> STRING:  HIDDEN
>

So why now this fails when 'letters' has more N's than in string, but
the first case did not fail when 'letters' had less D's than in string?

I think your problem specifications is not clear.

--Nasser

Re: How to check if letters are in a string?

[Trish Cayetano]

On Saturday, July 18, 2015 at 6:23:56 PM UTC+8, Nasser M. Abbasi wrote:
> On 7/18/2015 4:00 AM, Trish Cayetano wrote:
> > Hi,
> >
> > How do you check if (exact number of) letters are in a string?
> >
> > 1. This example should PASS because every letter is found in the string
> > LETTERS: HID
> > STRING:  HIDDEN
> >
> 
> I do not follow. The 'D' in 'letters' occur 1 time but it occurs
> 2 times in 'string'. So this is not the _exact number_ of
> letters in the string.
> 
> > 2. This example should FAIL because the letters contain 2 N's but the string only has 1 N.
> > LETTERS: NINE
> > STRING:  HIDDEN
> >
> 
> So why now this fails when 'letters' has more N's than in string, but
> the first case did not fail when 'letters' had less D's than in string?
> 
> I think your problem specifications is not clear.
> 
> --Nasser

Hi Nasser, 
Thanks... This is the concept of Text Twist Game if you know that game... 

Re: How to check if letters are in a string?

[Simon Clubley]

On 2015-07-18, Nasser M. Abbasi <nma@12000.org> wrote:
> On 7/18/2015 4:00 AM, Trish Cayetano wrote:
>> Hi,
>>
>> How do you check if (exact number of) letters are in a string?
>>
>> 1. This example should PASS because every letter is found in the string
>> LETTERS: HID
>> STRING:  HIDDEN
>>
>
> I do not follow. The 'D' in 'letters' occur 1 time but it occurs
> 2 times in 'string'. So this is not the _exact number_ of
> letters in the string.
>
>> 2. This example should FAIL because the letters contain 2 N's but the string only has 1 N.
>> LETTERS: NINE
>> STRING:  HIDDEN
>>
>
> So why now this fails when 'letters' has more N's than in string, but
> the first case did not fail when 'letters' had less D's than in string?
>
> I think your problem specifications is not clear.
>

I think the characters in "letters" are supposed to be a subset of the
characters in "string", 

To the OP: a couple of ways immediately come to mind.

1) Maintain a seperate boolean array whose size is the size of "string".
Set the position to true when a letter matches and ignore that position
when checking for subsequent letters.

or

2) Assign "string" to a temporary string and remove the matching character
from each pass. You use that temporary string when searching for subsequent
letters.

I really hope I have not just done your homework for you. :-)

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world

Re: How to check if letters are in a string?

[Björn Lundin]

Looks like I managed to mail this to the op instead of post it to c.l.a ...


On 2015-07-18 11:00, Trish Cayetano wrote:
> Is there another way how to check if (exact number of) letters are in
a string?
> Thank you very much!

declare
  My_Letters: string := "HID"
  My_String: string := "HIDDEN"
  Is_In_String : boolean := False;
begin
  for L in My_Letters'range loop
    Is_In_String := False;
    for S in My_String'range loop
      if My_Letters(L) = My_String(S) then
        Is_In_String := True;
        My_String(S) := ' '; --set to space, so letter is not reused
        exit; -- inner loop
      end if;
    end loop;
    exit when not Is_In_String;
  end loop;
  Text_io.put_Line("Is_In_String = "& Is_In_String'Img);
end;



not compiled, not tested but the spirit of it
should do what you want

-- -- Björn

-- 
--
Björn

Re: How to check if letters are in a string?

[Trish Cayetano]

On Saturday, July 18, 2015 at 7:35:13 PM UTC+8, björn lundin wrote:
> Looks like I managed to mail this to the op instead of post it to c.l.a ...
> 
> 
> On 2015-07-18 11:00, Trish Cayetano wrote:
> > Is there another way how to check if (exact number of) letters are in
> a string?
> > Thank you very much!
> 
> declare
>   My_Letters: string := "HID"
>   My_String: string := "HIDDEN"
>   Is_In_String : boolean := False;
> begin
>   for L in My_Letters'range loop
>     Is_In_String := False;
>     for S in My_String'range loop
>       if My_Letters(L) = My_String(S) then
>         Is_In_String := True;
>         My_String(S) := ' '; --set to space, so letter is not reused
>         exit; -- inner loop
>       end if;
>     end loop;
>     exit when not Is_In_String;
>   end loop;
>   Text_io.put_Line("Is_In_String = "& Is_In_String'Img);
> end;
> 
> 
> 
> not compiled, not tested but the spirit of it
> should do what you want
> 
> -- -- Björn
> 
> -- 
> --
> Björn

Thank you Nasser and Björn!
Björn nailed it!

You are one genius, Björn! It's working fine after a few tweaks (really minor like adding Ada and adding packages). Thank you so much!