Broken selection sort C

Question

I'm working on a selection sort.

My problem is that if you delete all of my code from "void sort", the program runs. As soon as you put all the code back in, "void sort" wont even get to the first "printf" function in "void sort". I don't know what is hanging everything up.

The second problem here is that this function should do this:

Run through they array[] with vars: x (starting point,) temp (temporary lowest number) and k (current number.) It should--for each iteration--start at x, set temp = x, set k = (x+1) and then k++ until it reaches the end of the array. If array[k] is less than array[temp] it should set temp equal to k. Then at the end: swap array[x] and array[temp] and start over at (x+1)

When it was working before, the only result I got was that x = 7 (the end of the list,) and it would only print the last number. :/ wat do

Also, not needed but a secondary question how the hell do I return the sorted array from a void function? Global vars? anything else?

#include <stdio.h>
#define SIZE 8

void sort(int array[], int size)
{
    printf("starting sort, declaring vars...");
    int temp, placeholder, x, k;
    printf("setting x...");
    x = 0;
    printf("size(%d), i(%d)", size, x);
    printf("starting sort loop...");
    while (x < (size - 1));
    {
        k = (x + 1);
        temp = x;
        while(k < size)
        {
            if(array[k] < array[temp])
                temp = k;
            k++;
        }
        printf("array[%d] is %d from array[%d]\n", x, array[temp], temp);
        placeholder = array[temp];
        array[temp]= array[x];
        array[x] = placeholder;
        printf("%d ", array[x]);
        x++;
    }
    printf("\n");
}

int main(void)
{
    int numbers[SIZE] = {4, 15, 16, 50, 8, 23, 42, 108 };
    int i;
    for (i = 0; i < SIZE; i++)
        printf("%d ", numbers[i]);
    printf("\ncounted and sorting...\n");
    sort(numbers, SIZE);
    for (int i = 0; i < SIZE; i++);
        printf("%d", numbers[i]);
    printf("\n");
    return 0;
}

try putting \n after all the print statements, your output might be getting buffered — Claudiu
– Claudiu, Commented Mar 25, 2013 at 17:46
You were completely right. I did that, now it freezes at the "while (x < (size - 1))" loop in "void sort." — user2208569
– user2208569, Commented Mar 25, 2013 at 17:51

raptortech97 · Accepted Answer · 2013-03-25 18:01:30Z

2

I don't know if this was a mistake in writing the question or in your code, but

while (x < (size - 1));

is incorrect. It does nothing, and so will loop infinitely. Take out the semicolon to get the intended effect. Similarly,

for (int i = 0; i < SIZE; i++);

Should not have that semicolon. Also, you can't declare i there in proper C, and i is already declared, so it's better to just leave it at for (i = 0; ....

answered Mar 25, 2013 at 18:01

raptortech97

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2 Comments

Claudiu Over a year ago

I think this is it. x and size never change in the loop, so it just iterates forever.

raptortech97 Over a year ago

Hi! If you found this answer to be the most helpful, you can click the check-mark on the left under the up- and down-arrows to "accept" the answer. This allows later visitors to see which answer was most helpful.

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