Simple C++ help...

Hey everyone.

I need to write some code that takes a two deimensional array, makes it a single dimension array and then sorts in ascending order. I need some help with the flatten part and here is what I have so far.

This code compiles and executes fine via Dev C++

Code:

---

#include <iostream>
#include <iomanip>
#include <math.h>
using namespace std;
int main()
{
const int NROWS = 4;
const int NCOLS = 5;
int i, j, s;
int first[NROWS][NCOLS] = {16,22,99,4,18,-258,4,101,5,98,105,6,15,2,45,33,88,72,16,3};
int SORT [19]; //Array of numbers
int sort; //Temp array number
// Insert the elements from the 2-dimmension in a single
for (i = 0; i < NROWS; i++)
    {  //beginning of outer loop
        cout << endl;    //start each row on a new line
        for (j = 0; j < NCOLS; j++)
        {  //beginning of inner loop
            SORT[0]=first[i][j];
            cout << sort << endl;
            }    //end of inner loop
            }    //end of outer loop
            cout << endl;
            return 0;
}

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Hmm, the two-dimensional array has 20 ints (4*5), but the onedimensional has room for 19? It should be int SORT[NROWS*NCOLS].

Code:

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SORT[0]=first[i][j];

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Why are you putting everything to SORT[0], shouldn't this be something like

Code:

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SORT[i*j+j] = first[i][j];

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Quote:

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Originally Posted by anon

Why are you putting everything to SORT[0], shouldn't this be something like

Code:

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SORT[i*j+j] = first[i][j];

---

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Or maybe:

Code:

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SORT[i*NCOLS+j] = first[i][j];

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Well, I made the changes you guys suggested but I still get crap on the output.

I re-wrote it for a single already to see what I get and this code works perfectly..

Code:

---

#include <iostream>
#include <iomanip>
#include <math.h>
using namespace std;

int bubbleSort( int[], int);

int main()
{


//const int NROWS = 4;
//const int NCOLS = 5;
//int first[NROWS][NCOLS] = {16,22,99,4,18,-258,4,101,5,98,105,6,15,2,45,33,88,72,16,3};
//int i, j;


const int ARR1 = 20;
int arr[ARR1]= {16,22,99,4,18,-258,4,101,5,98,105,6,15,2,45,33,88,72,16,3};
int i, j;

bubbleSort(arr, ARR1);

for (i = 0; i < ARR1; i++)
    {
        cout << endl;

            for( i = 0; i < ARR1; i++)
                  cout << " " << arr[i];
    }
            return 0;
}

int bubbleSort(int num[], int numel)
{
 int i, j, temp;

 for ( i = 0; i < (numel - 1); i++)
    {
      for ( j = 1; j < numel; j++)
      {
        if (num[j] < num[j-1])
        {
        temp = num[j];
        num[j] = num[j - 1];
        num[j-1] = temp;
        }
        }
        }
        }

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I have the 2-dimension part commented out so this code works, it is just with a single dimension.

I played around with it a little but still can get the double to flatten into a single and do the sort from there.

http://c-faq.com/aryptr/ary2dfunc2.html
bubbleSort( &first[0][0], NROWS * NCOLS );

The correct way would be to copy it to a proper 1-D array, sort it, then copy it back again.

If you've got the actual sorting working, then post your array copying code again.