#include <stdio.h>

#ifndef LENGTH
#include "helper.h"
#endif

int array[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };

size_t i, tmp;

void reverse(int x[])
{
    for (i = 0; i < LENGTH(array) / 2; i++) {
        tmp = x[i];
        x[i] = x[LENGTH(array) - 1 - i];
        x[LENGTH(array) - 1 - i] = tmp;
    }
}

int main()
{
    reverse(array);
    for (i = 0; i < LENGTH(array); i++)
        printf("[%d]", array[i]);
    return 0;
}