[JaKWaC]

I went out drinking with a few friends and being the nerds we are one of my friends posed the question:

How would you reverse a string without using, pointers, arrays, or c-strings.

After I got back I sat down and tried to tackle the question. Took me a little bit but after a while I came up with a solution.

I'd be interested to see what others would do to solve this question.

The terms "reverse" and "string" are used very loosely.

edit by ishkabible:
please remmber to post solutions in spoiler tags when
[ spoiler ]

your code here

[ /spoiler]

[Vishu Sukhdev]

Hi,
I haven't more knowledge of c and c++ but i did it in C#
like this

Spoiler

static void ReverseString()
        {
            Console.Write("Enter String = ");
            string sString = Console.ReadLine();

            int iLength = 0;
            string sReverse = null;

            iLength = sString.Length;

            for (int i = 0; i < iLength; i++)
            {
                string sTemp = sString.Substring(i, 1);
                sReverse = sTemp + sReverse;
            }
              Console.Write(sReverse);
              Console.Read();
        }

edit by ishkabible: please post all solutions to challenges in spoiler tags

This post has been edited by ishkabible: 21 April 2011 - 01:14 PM

[JaKWaC]

Your using a string at line 4

[muballitmitte]

what you posted is really confusing so it would be best if you write a clear problem statement. otherwise people will just write solutions like the following (pseudoc++)

Spoiler

char ch;
stack<char> s;

do 
{
   ch = getchar();
   s.push(ch);
} while (not_finished)

printStack(s);

This post has been edited by ishkabible: 21 April 2011 - 01:14 PM

[JaKWaC]

I'm pretty sure the idea is for the question to be fairly vague and open ended. There are a ton of ways you can solve the question and your solution works as far as I'm concerned.

[Bench]

the C++ standard library has got a built-in reverse function, that's less of a challenge and more like common sense to be honest

[baavgai]

Spoiler

void reverse() {
	char ch = getchar();
	if (ch!='\n') {
		reverse();
		printf("%c",ch);
	}
}

This post has been edited by ishkabible: 21 April 2011 - 01:15 PM

[JaKWaC]

baavgai, on 21 April 2011 - 12:36 PM, said:

Spoiler

void reverse() {
	char ch = getchar();
	if (ch!='\n') {
		reverse();
		printf("%c",ch);
	}
}

Ya thats basically what I did, but also put in a little check to not print out the new line character.

Spoiler

void reverse()
{
   char c;
	c = getchar();
	if(c != '\r' || c != '\n')
	{
		reverse();
	}
	else
	{
		// Stops it from printing out the newline/return
		return;
	}
	
	putchar(c);
}

Its the simplest way I can find to do it with no pointers at all (include nothing that relies on pointers as well)

This post has been edited by ishkabible: 21 April 2011 - 01:16 PM

[TMKCodes]

Duh, i'll just use integer type for the temp value and cast the character as integer and back. See no strings, pointers or arrays

[ishkabible]

just in case i haven't made my point, please post solutions in spoiler tags, just like code tags expect you use "spoiler" instead of "code"

[desirocks]

>>> str = 'ILOVELINUX'
>>> print str[::-1]
XUNILEVOLI

This is Python and this is called slicing...

[JohnS_]

function reverse(str)
	return string.reverse(str);
end

how about lua

[sk1v3r]

JohnS_, on 22 April 2011 - 04:21 AM, said:

function reverse(str)
	return string.reverse(str);
end

how about lua

Spoiler

function reverse(str)
    return str:reverse()
end

how about slightly less lua XD

[Krishs]

well , may be

Spoiler

for ( int i = 0 , len = strlen(s) ; i < len ; i++, len--)
s[i] ^= s[len] ^= s[i] ^= s[len] ;

[bloodzdevil]

Guys I dont know much of C++, just a beginner.
I'd do it like this:

Spoiler

char string[30];
gets(string);
strcpy(string,strrev(string));

This post has been edited by bloodzdevil: 31 January 2012 - 02:40 AM