#include<stdio.h>

int global1 = 300 ;
//---------------------------------------------------------------------------------------------------

void swap3( int** param1 )
{
 *param1 = &global1 ;
}

//---------------------------------------------------------------------------------------------------

void swap2( int* param1 )
{
  *param1 = 200 ;
}

//---------------------------------------------------------------------------------------------------
void swap1( int param1 )
{
	param1 = 200 ;
}
//---------------------------------------------------------------------------------------------------

int main()
{
	int x1 = 100 ;
	int* ptr1 ;
	int** doublePointer ;

	printf("%d\n" , x1 );
    swap1(  x1 ) ;
    printf("%d\n" , x1 );
    ptr1 = &x1 ;
    swap2( &x1 ) ;
    printf("%d\n" , x1 );
    //Change the value of a pointer.
    doublePointer =  &ptr1 ;
    swap3( doublePointer ) ;
    printf("%d\n" , **doublePointer );
    printf("%d\n" , *ptr1 );



    return(0)  ;

}