Programming Forums > Application Development > C++

layer · May 10th, 2005, 6:27 PM

Ok... So I'm learning a few new things, and think I know the problem with my code now, but don't know how to fix it

First, I'll start off by showing the code:

#include <cstdlib>
#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    fstream ostream;
    ostream.open("WL.txt", fstream::in);
    ofstream wstream ("WL.txt");
    char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    if (wstream.is_open())
    {
             for (int a = 1; a < strlen(abc); a++)
             {
                 for (int b = 1; b < strlen(abc); b++)
                 {
                     for (int c = 1; c < strlen(abc); c++)
                     {
                         for (int d = 1; d < strlen(abc); d++)
                         {
                             for (int e = 1; e < strlen(abc); e++)
                             {
                                 for (int f = 1; f < strlen(abc); f++)
                                 {
                                     for (int g = 1; g < strlen(abc); g++)
                                     {
                                         for (int h = 1; h < strlen(abc); h++) 
                                         {
                                             for (int i = 1; i < strlen(abc); i++)
                                             {
                                                 for (int j = 1; j < strlen(abc); j++)
                                                 {
                                                     char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j];
                                                     wstream << text << endl;
                                                     }
                                                 }
                                             }
                                         }
                                     }                
                                 }
                             }
                         }
                     }
                 }
             }
    wstream.close();
    ostream.close();
    return 0;
}

#include <cstdlib>
#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    fstream ostream;
    ostream.open("WL.txt", fstream::in);
    ofstream wstream ("WL.txt");
    char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    if (wstream.is_open())
    {
             for (int a = 1; a < strlen(abc); a++)
             {
                 for (int b = 1; b < strlen(abc); b++)
                 {
                     for (int c = 1; c < strlen(abc); c++)
                     {
                         for (int d = 1; d < strlen(abc); d++)
                         {
                             for (int e = 1; e < strlen(abc); e++)
                             {
                                 for (int f = 1; f < strlen(abc); f++)
                                 {
                                     for (int g = 1; g < strlen(abc); g++)
                                     {
                                         for (int h = 1; h < strlen(abc); h++) 
                                         {
                                             for (int i = 1; i < strlen(abc); i++)
                                             {
                                                 for (int j = 1; j < strlen(abc); j++)
                                                 {
                                                     char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j];
                                                     wstream << text << endl;
                                                     }
                                                 }
                                             }
                                         }
                                     }                
                                 }
                             }
                         }
                     }
                 }
             }
    wstream.close();
    ostream.close();
    return 0;
}

Ok, so this should make a permutation of every letter and character possible, correct? Now I know that running this, will soon blow up my computer because the text file will probably be bigger then my computers memory... But, it's for my math teacher to show him that C++ could calculate every single possible permutation of every number and letter possible

But when I compile this, it compiles fine. But when I run it, for like one second, I get a 1,000 Kb size file with "" in it... But why? I think it's because of this part right here:

(Toggle Plain Text)

char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j];

Well, could anyone tell me if I am either way off, or I am on track, but a logic error needs fixing? Thanks... :eek:

layer · May 10th, 2005, 6:49 PM

Oh yea, one more thing, when writing a console application, any way to get the X and Y coordinates of the cursor. I know how to set it, but how to you retrieve it? Thanks

Ooble · May 11th, 2005, 6:40 AM

Could I suggest using recursion?

spydoor · May 11th, 2005, 7:50 AM

(Toggle Plain Text)

char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j];

You're right this line is your problem, or at least part of it (I didn't notice anyting else wrong, but didn't look).

I guess you're trying to concatenate a seris of single characters using &&'s and assign them to a string?

well you can't use && to do that, and you can't assign a string to a single char variable.

what you are doing is assigning the result of an expression to the variable text, which will always equal 1, and then printing it as a character, so check the ascii value corresponding to 1 to see why it's printing garbage.

off the top of my head I can't think of an elegant way to concatenate the characters. you could do something like

(Toggle Plain Text)

char text[10];
text[0] = abc[a];
text[1] = abc[b];
...
text[9] = '\0';

or you can just directly print the characters without the temp variable at all

(Toggle Plain Text)

wstream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl;

I would try running for a smaller subset of the alphabet when testing. As you've already admitted yourself you are going to run into, at the least, memory issues. You're already at what ?... 62^9 iterations with the code you have there.

layer · May 11th, 2005, 2:13 PM

Ok... I tried using the second method by just writing them directly, spydoor... And I get the right output, except in the output, before the actual numbersd and letters I want, I get this:

Quote:

0x22fdd0bbbbbbbb

Here's a small portion of the file (theres like tons more times a million that gets outputted in a second...)

Quote:

0x22fdd0bbbbbbbbbb
0x22fdd0bbbbbbbbbc
0x22fdd0bbbbbbbbbd
0x22fdd0bbbbbbbbbe
0x22fdd0bbbbbbbbbf
0x22fdd0bbbbbbbbbg
0x22fdd0bbbbbbbbbh
0x22fdd0bbbbbbbbbi
0x22fdd0bbbbbbbbbj
0x22fdd0bbbbbbbbbk
0x22fdd0bbbbbbbbbl
0x22fdd0bbbbbbbbbm
0x22fdd0bbbbbbbbbn
0x22fdd0bbbbbbbbbo
0x22fdd0bbbbbbbbbp
0x22fdd0bbbbbbbbbq
0x22fdd0bbbbbbbbbr
0x22fdd0bbbbbbbbbs
0x22fdd0bbbbbbbbbt
0x22fdd0bbbbbbbbbu
0x22fdd0bbbbbbbbbv
0x22fdd0bbbbbbbbbw
0x22fdd0bbbbbbbbbx

But I dont want the "0x22fdd0bbbbbbbb"... I just want the "bbv". Anyway to do this? Or do you know why I get the 0x22fdd0bbbbbbb?

Again, thanks

EDIT: Also, Ooble, I just skimmed over a small Recursion tutorial, because I haven't touched up on that yet, I mean, I know what it is and all, just gotta find the right way to use it

Thanks for the suggestion though!

spydoor · May 11th, 2005, 3:11 PM

No, I don't know a specfic reason why, but it is odd that you opened two streams to the same file, and one of them presumable for reading in input (fstream::in), which you never use.

This may be the cause of your problem, but I tried your code that way and it actually did work for me.

Another problem may be where you're actually printing the charcters (would have to see your code);

Here's an example of code that should work using only one fstream.

(Toggle Plain Text)

    fstream ostream;
    ostream.open("WL.txt" , fstream::out);

    char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    if (ostream.is_open())
    {
		//all the for loops...
				ostream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl;												
		//close loops...
    }

    ostream.close();
    return 0;

layer · May 11th, 2005, 3:30 PM

Hmm... The new code you supplied took away the 0x22 but still leaves an extra 5 or 6 b's... Maybe I'll just trim some characters out of the file when outputting them, cause I gotta go now

Thanks for your help though spydoor!

spydoor · May 12th, 2005, 8:26 AM

you're printing too many b's because your algorithm for finding all the permutations is wrong. A quick search turned up a couple of solutions to the problem, iteratively and recursively. Your solution looks like it would end up printing N^N lines while it should be N!

http://www.google.com/search?q=strin...ions+iterative

brkstf · May 12th, 2005, 3:48 PM

you can also do this using bytes, iterating the bytes, and outputing them by casting them as chars. something like this

byte someThing=0;
for(int x=0; x<256; x++)
{
cout <<char(byte);
byte++;
}

of course, you'd need to test the byte for value within a range.

you could likewise use an array of bytes
byte something[6];

tempest · May 12th, 2005, 4:57 PM

how about making:

(Toggle Plain Text)

byte someThing=0;
for(int x=0; x<256; x++)
{
cout <<char(byte);
byte++;
}

A lot simpler...

(Toggle Plain Text)

for(int i=0;i<256;i++)
    cout << (char)i;

May 10th, 2005, 6:27 PM	#1
layer Hobbyist Programmer Join Date: Feb 2005 Posts: 112 Rep Power: 4	For loops, a lot, outputting weird characters Ok... So I'm learning a few new things, and think I know the problem with my code now, but don't know how to fix it First, I'll start off by showing the code: (Toggle Plain Text) #include <cstdlib> #include <iostream> #include <fstream> using namespace std; int main() { fstream ostream; ostream.open("WL.txt", fstream::in); ofstream wstream ("WL.txt"); char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; if (wstream.is_open()) { for (int a = 1; a < strlen(abc); a++) { for (int b = 1; b < strlen(abc); b++) { for (int c = 1; c < strlen(abc); c++) { for (int d = 1; d < strlen(abc); d++) { for (int e = 1; e < strlen(abc); e++) { for (int f = 1; f < strlen(abc); f++) { for (int g = 1; g < strlen(abc); g++) { for (int h = 1; h < strlen(abc); h++) { for (int i = 1; i < strlen(abc); i++) { for (int j = 1; j < strlen(abc); j++) { char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; wstream << text << endl; } } } } } } } } } } } wstream.close(); ostream.close(); return 0; } #include <cstdlib> #include <iostream> #include <fstream> using namespace std; int main() { fstream ostream; ostream.open("WL.txt", fstream::in); ofstream wstream ("WL.txt"); char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; if (wstream.is_open()) { for (int a = 1; a < strlen(abc); a++) { for (int b = 1; b < strlen(abc); b++) { for (int c = 1; c < strlen(abc); c++) { for (int d = 1; d < strlen(abc); d++) { for (int e = 1; e < strlen(abc); e++) { for (int f = 1; f < strlen(abc); f++) { for (int g = 1; g < strlen(abc); g++) { for (int h = 1; h < strlen(abc); h++) { for (int i = 1; i < strlen(abc); i++) { for (int j = 1; j < strlen(abc); j++) { char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; wstream << text << endl; } } } } } } } } } } } wstream.close(); ostream.close(); return 0; } Ok, so this should make a permutation of every letter and character possible, correct? Now I know that running this, will soon blow up my computer because the text file will probably be bigger then my computers memory... But, it's for my math teacher to show him that C++ could calculate every single possible permutation of every number and letter possible But when I compile this, it compiles fine. But when I run it, for like one second, I get a 1,000 Kb size file with "" in it... But why? I think it's because of this part right here: (Toggle Plain Text) char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; Well, could anyone tell me if I am either way off, or I am on track, but a logic error needs fixing? Thanks... :eek:

May 11th, 2005, 6:40 AM	#3
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Could I suggest using recursion? __________________ Me :: You :: Them

May 11th, 2005, 7:50 AM	#4
spydoor Programmer Join Date: Feb 2005 Posts: 64 Rep Power: 4	(Toggle Plain Text) char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; char text = abc[b] && abc[c] && abc[d] && abc[e] && abc[f] && abc[g] && abc[h] && abc[i] && abc[j]; You're right this line is your problem, or at least part of it (I didn't notice anyting else wrong, but didn't look). I guess you're trying to concatenate a seris of single characters using &&'s and assign them to a string? well you can't use && to do that, and you can't assign a string to a single char variable. what you are doing is assigning the result of an expression to the variable text, which will always equal 1, and then printing it as a character, so check the ascii value corresponding to 1 to see why it's printing garbage. off the top of my head I can't think of an elegant way to concatenate the characters. you could do something like (Toggle Plain Text) char text[10]; text[0] = abc[a]; text[1] = abc[b]; ... text[9] = '\0'; char text[10]; text[0] = abc[a]; text[1] = abc[b]; ... text[9] = '\0'; or you can just directly print the characters without the temp variable at all (Toggle Plain Text) wstream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl; wstream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl; I would try running for a smaller subset of the alphabet when testing. As you've already admitted yourself you are going to run into, at the least, memory issues. You're already at what ?... 62^9 iterations with the code you have there. Last edited by spydoor; May 11th, 2005 at 7:59 AM.

May 11th, 2005, 3:11 PM	#6
spydoor Programmer Join Date: Feb 2005 Posts: 64 Rep Power: 4	No, I don't know a specfic reason why, but it is odd that you opened two streams to the same file, and one of them presumable for reading in input (fstream::in), which you never use. This may be the cause of your problem, but I tried your code that way and it actually did work for me. Another problem may be where you're actually printing the charcters (would have to see your code); Here's an example of code that should work using only one fstream. (Toggle Plain Text) fstream ostream; ostream.open("WL.txt" , fstream::out); char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; if (ostream.is_open()) { //all the for loops... ostream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl; //close loops... } ostream.close(); return 0; fstream ostream; ostream.open("WL.txt" , fstream::out); char abc[70] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; if (ostream.is_open()) { //all the for loops... ostream << abc[b] << abc[c] << abc[d] << abc[e] << abc[f] << abc[g] << abc[h] << abc[i] << abc[j] << endl; //close loops... } ostream.close(); return 0; Last edited by spydoor; May 11th, 2005 at 3:17 PM.

May 12th, 2005, 4:57 PM	#10
tempest Programming Guru Join Date: Oct 2004 Posts: 1,041 Rep Power: 5	how about making: (Toggle Plain Text) byte someThing=0; for(int x=0; x<256; x++) { cout <<char(byte); byte++; } byte someThing=0; for(int x=0; x<256; x++) { cout <<char(byte); byte++; } A lot simpler... (Toggle Plain Text) for(int i=0;i<256;i++) cout << (char)i; for(int i=0;i<256;i++) cout << (char)i; __________________

May 10th, 2005, 6:49 PM	#2
layer Hobbyist Programmer Join Date: Feb 2005 Posts: 112 Rep Power: 4	Oh yea, one more thing, when writing a console application, any way to get the X and Y coordinates of the cursor. I know how to set it, but how to you retrieve it? Thanks

May 11th, 2005, 3:30 PM	#7
layer Hobbyist Programmer Join Date: Feb 2005 Posts: 112 Rep Power: 4	Hmm... The new code you supplied took away the 0x22 but still leaves an extra 5 or 6 b's... Maybe I'll just trim some characters out of the file when outputting them, cause I gotta go now Thanks for your help though spydoor!

May 12th, 2005, 8:26 AM	#8
spydoor Programmer Join Date: Feb 2005 Posts: 64 Rep Power: 4	you're printing too many b's because your algorithm for finding all the permutations is wrong. A quick search turned up a couple of solutions to the problem, iteratively and recursively. Your solution looks like it would end up printing N^N lines while it should be N! http://www.google.com/search?q=strin...ions+iterative

May 12th, 2005, 3:48 PM	#9
brkstf Programmer Join Date: Feb 2005 Posts: 89 Rep Power: 4	you can also do this using bytes, iterating the bytes, and outputing them by casting them as chars. something like this byte someThing=0; for(int x=0; x<256; x++) { cout <<char(byte); byte++; } of course, you'd need to test the byte for value within a range. you could likewise use an array of bytes byte something[6];

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Programming Forums > Application Development > C++

For loops, a lot, outputting weird characters