posted                   

quote:

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that would be a little shorter than half the time the universe has existed.

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Or roughly one million times as long, depending on whose numbers you believe.

Posts: 10645 | Registered: Jul 2004  |  IP: Logged | 

posted                  

quote:

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Originally posted by King of Men:
Or you could write a virus to take over large parts of the Internet for you, making a massively-parallel computer - perfect for this kind of very subdivisible problem - that could do it in a mere million years or so.

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Posts: 7021 | Registered: Nov 1999  |  IP: Logged | 

posted                   

quote:

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Originally posted by BandoCommando:
You all impress the heck out of me.

The best I ever got in programming was a modified BASIC on my TI-86 that I used to simplify calculus. Oh, and there was a brief fling with Hypercard scripts in middle school. I used to drive the librarians crazy with scripts that would force restarts after random periods of time elapsed. But then, I would win their adulation and praises by magically 'fixing' the machines.

You all amaze me.

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Likewise. I wrote a Magic 8 Ball program from scratch on my TI-82 back in 9th grade.

Posts: 1945 | Registered: Jul 2005  |  IP: Logged | 

posted                   

quote:

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Originally posted by Dagonee:
BTW, if you did this recursively, I see a stack overflow in your future.

If you didn't do this recursively, then either a memory allocation failure or stack overflow is in your future.

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Posts: 1170 | Registered: Jan 2003  |  IP: Logged | 

posted             

code:

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/*************************************************************

	Permuation Assignment
	Take an input string N of ABC...XYZ
	and print out every permutation
	of that input string.

	Blayne Bradley
	0463737



*************************************************************/


#include <iostream>
#include <cstring>

using namespace std;

//Globals, constants, arrays
const int MAX = 27;
char Beta[MAX];
char Alpha[MAX] = { "ABCDEFGHIJKLMNOPQRSTUWVXYZ" };
char App[MAX] = "\0";

int N = 0;

//Functions
void Perm( char Beta[MAX], char append[MAX] );

void main()
{

	int in = 0;

	cout << "Please select how many letters you wish to"
		<< " permute N: ";
	cin >> in; // N

	// Error checking
	while ( in < 0 || in > 26 )
	{

		cout << "Invalid Input: Please select how many letters you wish to"
			<< " permute N: ";
		cin >> in;


	}

	
	cout << "        N Letters are: ";

	// copying the selected N letters into the 
	// array passed to the Perm function.
	for ( int counter = 0; counter < in; counter++)
	{
		Beta[counter] = Alpha[counter];
		// to show the original string
		cout << Beta[counter];
	}

	cout << endl;

	cout << "********************************" << endl << endl;
	
	//the Permutation function
	Perm(Beta, App);
	cout << endl;
	cout << N << " Permuations: " << in << " Letters Chosen" << endl << endl;
	system("pause");

}
/*
	recursively do permutations.
*/
void Perm( char StringB[MAX], char To_App[MAX]  )
{
	// find the length of the string passed
	int len = strlen(StringB);


	if ( len > 0 )
	{
	
		for ( int count = 0; count < len; count++ )
		{
			// create a pointer array because length at runtime
			// isnt definable so it is more efficient to create
			// a pointer array dynamically with a more specific
			// size.
			char* string1 = new char[len+1];

			int counter;
			int next;

			/* within this loop for the length of the loop
				assign letters from StringB -> String1

			*/
			for ( counter = 0, next = 0; counter < len; counter++, next++ )
			{
					if ( counter == count )
					{
						string1[counter] = StringB[++next];
						continue;
					}
					else
					{
						string1[counter] = StringB[next];
					}
			}

			string1[counter] = '\0';  //appending null value to end of array

			int length = strlen(To_App);
			char* To_App1 = new char [length+2]; //creating the append pointer array
												 //dynamically

			// copy the passed Append string to the
			// new Append string at length size.
			strncpy(To_App1, To_App, length );
			To_App1[length] = StringB[count];
			To_App1[length+1] = '\0';

			// Perm calls Perm recursively here
			Perm( string1, To_App1 );

			// delete the used pointer arrays as you pop off the stack.
			delete []string1;
			delete []To_App1;

		}
	}
	else
	{
		// Cout each completed
		// Permuation when size is zero.
		cout << To_App << endl;

		N++;
	}
}

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IP: Logged | 

posted                   

quote:

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Likewise. I wrote a Magic 8 Ball program from scratch on my TI-82 back in 9th grade.

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I wrote a pretty neat little maze RPG on my TI-83 in high school. After about 10 minutes of playing you can tell when I got bored because every option leads to a hilarious death.

Other than that, I like to come in these threads and marvel at how little I know about programing. It's a geek to me- err, Greek, that is.

Posts: 2596 | Registered: Jan 2006  |  IP: Logged | 

posted                   

code:

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#!/usr/bin/env python

import sys

word = sys.argv[1]

def permute(word):
  if len(word) == 0:
    yield word
  else:
    for letter_index in range(len(word)):
      for permutation in permute(word[:letter_index] + word[letter_index + 1:]):
        yield word[letter_index] + permutation

for permutation in permute(word):
  print permutation

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Posts: 15770 | Registered: Dec 2001  |  IP: Logged |