Constant pointer :

 // in these way we can alter the value of x using pointer

#include <stdio.h>

int main()

{

   const int x = 22;

   int *p ;

   p = &x;

   *p = 155;

    

    printf("%d is the value of x" , x);

    return 0;

}

*********"""""***********"""""""*********

// in these way we can alter the value of  *p using another  pointer q;

#include <stdio.h>

int main()

{

   const int x = 22;

    const int *p ;

    int *q;

    

   p = &x;

   //*p = 155;

    q = &x;

    *q= 200;

    printf("%d is the value of x" , x);

    return 0;

}