#include <stdio.h>

int main() {
int a=10,b=20;
int *ptr;
ptr=&a;
printf("Value of ptr:%d\n",*ptr);
*ptr=20;
printf("new value of a:%d\n",a);
int arr[3]={10,20,30};
int *p;
p=arr;
for(int i=0;i<3;i++)
{
    printf("arithmetic:%d\n",i,*(p+i));
}
p++;
printf("vale to arr[1]:%d\n",*p);
p++;
printf("value to arr[2]:%d\n",*p);
return 0;
}