bubble sort directional problems

I want to sort an array using bubble sort. I know it's the slowest but i have only 5-10 elements so it's fast enough. My algorithm for bubble sort works cause if I code this

Code:

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void Bubble(int array[], int length, int direction)
{
        int i, j;
       
        for (i=0; i<(length-1); i++)
        {
                for (j=0; j<(length-i-1); j++)
                {
                        if (array[j] > array[j+1])
                                Swap(&array[j], &array[j+1]);
                }
        }
}

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for the array

Code:

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884, 275, 470, 890, 860

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i get as expected

Code:

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275, 470, 860, 884, 890

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I also want the user to determine in which direction the array is sorted, up or down, but here is the problem because I get a stupid response.

Code:

---

void Bubble(int array[], int length, int direction)
{
        int i, j;
       
        for (i=0; i<(length-1); i++)
        {
                for (j=0; j<(length-i-1); j++)
                {
                        if (direction == 1)
                                if (array[j] > array[j+1])
                                  Swap(&array[j], &array[j+1]);
                        else
                                if (array[j] < array[j+1])
                                        Swap(&array[j], &array[j+1]);
                }
        }
}

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but now i get this

Code:

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860, 890, 470, 275, 884

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and it's ming boggling why!!

Quote:

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Originally Posted by budala

Code:

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                        if (direction == 1)
                                if (array[j] > array[j+1])
                                  Swap(&array[j], &array[j+1]);
                        else
                                if (array[j] < array[j+1])
                                        Swap(&array[j], &array[j+1]);

---

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Hey,

the C compiler always binds the "else" to the inner-most if, so that your else is not bound to the "if (direction == 1)". Your indention however easily leads to the assumption that your code must be correct. Instead rewrite your code as follows:

Code:

---

                        if (direction == 1)
                        {
                                if (array[j] > array[j+1])
                                  Swap(&array[j], &array[j+1]);
                        }
                        else
                        {
                                if (array[j] < array[j+1])
                                        Swap(&array[j], &array[j+1]);
                        }
}

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- Andi -