Sorting an Array in C from low to high (without using qsort)

I have a functions, which takes an Array开发者_JAVA技巧 of numbers, and sort them from low to high. So far, I have this algorithm, however the output isn't what I'm expecting. Can someone shed some light on it. I cannot use any C library functions.

/* 
   Sort "count" numbers stored in array numbers[] in non-decreasing order.
   There may be duplicate numbers in the array.
   You may use any sorting algorithm that you know.
 */

void sort( double numbers[], int count )
{
    int i, j, k;
    //printf("%d", count);

    double temp;
    do{
        j = 0;  
        for (i = 0;i<=count;i++){
                if (numbers[i] > numbers[i+1]){//this was numbers[k], which was an error
                    j = 1;
                    temp = numbers[i];
                    numbers[i] = numbers[i+1];
                    numbers[i+1] = temp;
                }
            }
    } while (j == 1);
}

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The condition in for loop i<=count is incorrect.

Valid index in the array are 0 to count-1.
Since you are accessing value at index i+1 in the loop:

if (numbers[i] > numbers[i+1])

i can take the value from 0 to count-2, so change the condition to i<=count-2 or i<count-1

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You are trying to implement the bubble sort algorithm. Read this to understand what your code is missing.

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The value of k is used, but the variable is never initialized or assigned to. At some point your code will try to access the value numbers[count], when an array containing count elements has maximum index count-1

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You haven't initalised k.

The algorithm will stop as soon as it has moved just one number. You need to move all of them.

I think you are missing a for loop on k outside the while loop, but as I'm not entirely sure what you're trying to do here I can't be sure.

Why can't you implement your own qsort() function? Is that allowed? Try reading up on a few sorting algorithms online.

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if (numbers[i] > numbers[k]){

should probably be

if (numbers[i] > numbers[i+1]){

k isn't used at all.

for (i = 0;i <= count;i++){

should probably be

for (i = 0; i < count-1;i++){

as there are only elements from 0 to count-1, and then you are comparing to the next one. The name for j is crap. Make it a boolean called didSwap. And then rethink about your codition, maybe it's just the other way around...