关于C语言中交换两个数的代码探讨

#include <stdio.h>

// There is no need to allocate the third position for temp
void reverse_array(int a[], int cnt)
{
int first, last;
for (first=0, last=cnt-1; first<last; first++, last--)
{
inplace_swap(&a[first], &a[last]);
}
}

int main()
{
int a[5] = {1,2,3,4,5};
reverse_array(a, 5);
for (int i=0; i<5; i++)
{
printf("%d ", a[i]);
}
printf("\n");
return 0;
}

void inplace_swap(int *x, int *y)
{
int itmp = *x;
*x =  *y;
*y = itmp;
}

void inplace_swap(int *x, int *y)
{
int *ptmp = x;
x =  y;
y = ptmp;
}