C string array bubble sort returns the input as output

Question

in my function I am given a string array where it needs to be sorted via a specific ruleset which is also given - the main function works and the rule comparison ones work as well but the bubble sort keeps returning the input as output and I can't figure out why.

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
void swap(char** s1, char** s2) 
{
    char** temp = s1;
    s1 = s2;
    s2 = temp;
}
main()
{
    int i, j; 
    char** arr_of_strings = malloc(3 * sizeof(char*));//I allocated the array 
    arr_of_strings[0] ="wonder_woman";//with malloc and loops originally.
    arr_of_strings[1] ="batman";
    arr_of_strings[2] ="superman";
    for (i = 0; i <2; i++)//the bubble array process:
    {
        for (j = 0; j < 3 - i - 1; j++)
        {
            if (strcmp(arr_of_strings[i], arr_of_strings[j]) > 0) 
            {
                swap(&arr_of_strings[j], &arr_of_strings[j + 1]);
            }
        }
    }
     printf("The sorted strings are:
"); //printing the function
    for (int k = 0; k < 3; k++) {
        printf("%s
", arr_of_strings[k]);
    }

}

output example:

The sorted strings are:
wonder_woman
batman
superman

question from:https://stackoverflow.com/questions/65923005/c-string-array-bubble-sort-returns-the-input-as-output

Answer 1

I think you have a problem with your swap function' or the way you call it. anyway, this implementation works:

#include <stdio.h>
#include <malloc.h>
#include <string.h>

#define SIZE 3

int main()
{
    int i, j; int n=SIZE; //n is a user input in the original program.
    char temporary_string[32];
    char* arr_of_strings[SIZE];
char* temp = NULL;

//input data
for (int l = 0; l < 3; l++)
{
    scanf("%s", temporary_string);
    arr_of_strings[l] = malloc(((strlen(temporary_string) + 1) *sizeof(char)));
    strcpy(arr_of_strings[l], temporary_string);
    temporary_string[0] = '';
}

//the actual sort
for (i = 0; i < n - 1; i++)
{
    for (j = 0; j < SIZE - i - 1; j++)
    {
        if (strcmp(arr_of_strings[j], arr_of_strings[j + 1]) > 0) //simplification
        {
           //swap
           temp = arr_of_strings[j];
           arr_of_strings[j] = arr_of_strings[j + 1];
           arr_of_strings[j + 1] = temp;
        }
    }
}

printf("The sorted strings are:
");
for (int i = 0; i < n; i++) {
    printf("%s
" , arr_of_strings[i]);
}
 // free allocated memory
 for (int i = 0; i < n; i++) {
     free(arr_of_strings[i]);
 }
}

I hope it helps, if you have quastions I would be happy to answer =)