Please help me find an error in the C program using the gdb debugger (not using GPT chat)

#include <stdio.h>
void swap(int* a, int* b)
{
int tmp = *a;
*a = *b;
*b = tmp;
}
void bubble_sort(int* array, int size)
{
int i, j;
for (i = 0; i < size - 1; ++i) {
for (j = 0; j < size - i; ++j) {
if (array[j] > array[j + 1]) {
swap(&array[j], &array[j + 1]);
}
}
}
}
int main()
{
int array[100] = {10, 15, 5, 4, 21, 7};

bubble_sort(array, 6);
int i
for (i = 0; i < 6 ; ++i) {
printf("%d ", array[i]);
}
printf("\n");
return 0;
}

C

#include <stdio.h>

void swap(int* a, int* b)

{

    int tmp = *a;

    *a = *b;

    *b = tmp;

}

void bubble_sort(int* array, int size)

{

    int i, j;

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

        for (j = 0; j < size - i; ++j) {

            if (array[j] > array[j + 1]) {

                swap(&array[j], &array[j + 1]);

            }

        }

    }

}

int main()

{

    int array[100] = {10, 15, 5, 4, 21, 7};

 

    bubble_sort(array, 6);

    int i

    for (i = 0; i < 6 ; ++i) {

        printf("%d ", array[i]);

    }

    printf("\n");

    return 0;

}