initializing vector of char * s

[istemihan]

Hello, I am trying to solve this puzzle: http://www.puzzleup.com/2015/puzzle/?13

to do that, I want to calculate all the possible codes and pass them in a vector

You will produce a set of 7-letter codes using the the letters A, B, C, D, E, F and G.

So I tried to create vector of char arrays. The code is shared below:

#include <iostream>
#include <string>
#include <vector>
#include <array>
#include <cmath>

char letters[] = {'a','b','c','d','e','f','g'};

char * tempArr;
char * pastArr;


std::vector<char * > deneme;
char s1[] = {'a', 'b'};
char s2[] = {'c', 'd'};

void calculateAllPossibilities(int depth, int lastDepth)
{
    //depth 1 den baþlayacak
    for( int i = 0; i < sizeof(letters); i++ )
    {
        //

        if ( depth != 1 && depth != lastDepth )
        {
            //
            tempArr = new char[depth];
            for( int j = 0; j < depth-1; j++ )
            {
                //
                *tempArr = pastArr[j];
                tempArr++;
            }
            *tempArr = letters[i];
            delete pastArr;
            pastArr = new char[depth];
            for( int k = 0; k < depth; k++ )
            {
                //
                *pastArr = tempArr[k];
                pastArr++;
            }
            delete tempArr;
            calculateAllPossibilities(depth + 1, lastDepth );
        }
        else if( depth == lastDepth )
        {
            //
            tempArr = new char[depth];
            for( int k = 0; k < depth - 1; k++ )
            {
                //
                *tempArr = pastArr[k];
                tempArr++;
            }
            *tempArr = letters[i];
            deneme.push_back(tempArr);
            delete tempArr;
        }
        else if( depth == 1 )
        {
            //
            pastArr = new char[depth];
            *pastArr = letters[i];
            delete tempArr;
            calculateAllPossibilities(depth + 1, lastDepth );
        }

    }
}

int main()
{

    calculateAllPossibilities(1,7);

    std::cout << deneme[0][2];

    return 0;
}

The problem is, when I try to cout the values of deneme vector, it gives me different thing in each compilation. Like those: ":", "_", "X", "2" :)

What am I doing wrong here? LB and Helios?

[istemihan]

If you want your computer to go crazy, run this code:

#include <iostream>
#include <string>
#include <vector>
#include <array>
#include <cmath>

char letters[] = {'a','b','c','d','e','f','g'};

char * tempArr;
char * pastArr;


std::vector<char * > deneme;
char s1[] = {'a', 'b'};
char s2[] = {'c', 'd'};

void calculateAllPossibilities(int depth, int lastDepth)
{
    //depth 1 den baþlayacak
    for( int i = 0; i < sizeof(letters); i++ )
    {
        //

        if ( depth != 1 && depth != lastDepth )
        {
            //
            tempArr = new char[depth];
            for( int j = 0; j < depth-1; j++ )
            {
                //
                *tempArr = pastArr[j];
                tempArr++;
            }
            *tempArr = letters[i];
            for( int x = 0; x < depth; x++ )
            {
                //
                std::cout << tempArr[x] << ",";
            }
            std::cout << std::endl;
            delete pastArr;
            pastArr = new char[depth];
            for( int k = 0; k < depth; k++ )
            {
                //
                *pastArr = tempArr[k];
                pastArr++;
            }
            delete tempArr;
            calculateAllPossibilities(depth + 1, lastDepth );
        }
        else if( depth == lastDepth )
        {
            //
            tempArr = new char[depth];
            for( int k = 0; k < depth - 1; k++ )
            {
                //
                *tempArr = pastArr[k];
                tempArr++;
            }
            *tempArr = letters[i];
            for( int x = 0; x < depth; x++ )
            {
                //
                std::cout << tempArr[x] << ",";
            }
            std::cout << std::endl;
            deneme.push_back(tempArr);
            delete tempArr;
        }
        else if( depth == 1 )
        {
            //
            pastArr = new char[depth];
            *pastArr = letters[i];
            std::cout << pastArr[0] << std::endl;
            delete tempArr;
            calculateAllPossibilities(depth + 1, lastDepth );
        }

    }
}

int main()
{

    calculateAllPossibilities(1,7);

    std::cout << deneme[0][2];

    return 0;
}

First time I encounter something like this. It makes PC beeps! WTF did I do?!

[MiiNiPaa]

It makes PC beeps! WTF did I do?!

More simple way to make computer beep: std::cout << '\a';
I did not look at your code yet, but it seems that you are accessing uninitialized memory.

EDIT: problem number 1: you have wrong delete here.
Remember: if you use new, use delete. If you use new[], use delete[]. In other words arrays should be deleted with delete[]

Problem 2:

tempArr = new char[depth];
tempArr++;
delete[] tempArr;

You should pass to delete exact same unchanged pointer, which was returned by new.

Problem 3:

deneme.push_back(tempArr);
delete[] tempArr;

deneme now contains invalid pointer: pointing to deleted data.

[istemihan]

@MiiNiPaa

thanks for the reply. I used std::string instead of char* and problem solved.