/* chlng.c
 * CS201 - by RA
 */

#include <stdio.h>

int main(void)
{int result; 
 int z=3, y=2, x=0; 
 int * ptrC, * ptrB, * ptrA; 	
 /*what if we would write "int * ptrC, ptrB, ptrA;" instead? */

 printf ("\nValues of x: %d, y: %d, z: %d",x, y, z);
 printf ("\nAddress of x: %p, y: %p, z: %p",&x, &y, &z);

 ptrA = &x;	
 x++; //i.e. x = x + 1	
 printf ("\n\nAfter ptrA=&x and x++ are performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);

 ptrA++;	
 printf ("\n\nAfter ptrA++ is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);

 result= *ptrA++;    // IMPORTANT to know what is going to be performed first!	
 printf ("\n\nAfter result= *ptrA++ is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);
 printf ("\nValue returned by result: %d",*ptrA);

 ptrB = ptrA - 2;	
 printf ("\n\nAfter ptrB=ptrA-2 is performed");
 printf ("\nValue returned by *ptrB: %d, ptrB points at: %p",*ptrB, ptrB);
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);

 ptrC = &(*ptrA); //the same as prtC=ptrA;
 printf ("\n\nAfter ptrC=&(*ptrA) is performed");
 printf ("\nValue returned by *ptrC: %d, ptrC points at: %p",*ptrC, ptrC);
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);

 ptrC = ptrA;
 printf ("\n\nAfter ptrC=ptrA is performed");
 printf ("\nValue returned by *ptrC: %d, ptrC points at: %p",*ptrC, ptrC);
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);

 *(ptrA--)=7;
 printf ("\n\nAfter *(ptrA--)=7 is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);
 printf ("\nValue that was modified *(ptrA+1): %d, ptrA+1 points at: %p",*(ptrA+1), ptrA+1);

 *(--ptrA)=9;
 printf ("\n\nAfter *(--ptrA)=9 is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p",*ptrA, ptrA);
 
 // ptrB= &ptrA;
 // warning: assignment from incompatible pointer type

 ptrB= (int *) &ptrA;
 printf ("\n\nAfter ptrB= (int *) &ptrA is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p, address of ptrA: %p",*ptrA, ptrA, &ptrA);
 printf ("\nAddress we can retrieve using *ptrB: %p, ptrB points at: %p",*ptrB, ptrB);

 // ptrC= *ptrB;
 // warning: assignment makes pointer from integer without a cast

 ptrC= (int *) *ptrB;
 printf ("\n\nAfter ptrC= (int *) *ptrB is performed");
 printf ("\nValue returned by *ptrA: %d, ptrA points at: %p, address of ptrA: %p",*ptrA, ptrA, &ptrA);
 printf ("\nAddress we can retrieve using *ptrB: %p, ptrB points at: %p",*ptrB, ptrB);
 printf ("\nValue we can retrieve using *ptrC: %d, ptrC points at: %p",*ptrC, ptrC);

 printf("\n");
 exit(0);
 }