#include<stdio.h>

void aa()
{
         int a[] = {1,1,2,3,5,8,13,21,34,55};
     int* ap1 = &a[1];
     int* ap5 = &a[5];
     printf("%d\n", *(ap1+3));
     printf("%d\n", *(ap5-3));
     printf("%d\n", (ap5-ap1));
     printf("%d\n", ap1<ap5);
     printf("%d\n", *ap1<*ap5);
}

void bb()
{
    int a[] = {1,1,2,3,5,8,13,21,34,55};
    int* p = &a[0];
    int* q = &a[9];
    int t;
    while (p < q)
    {
	t = *p;
	*(p++) = *q;
	*(q--) = t;
    }
    for (int i=0; i<10; i++)
    {
	printf("%d\n", a[i]);
    }
}
int main(int argc, char * argv[])
 {
     switch (argv[1][0])
     {
	 case '1':
	     aa();
	     break;
     case '2':
	 bb();
	 break;
     }
 }