Pointer question

I am learning C and I feel a bit confused by pointer. i write this simple code to test:

My idea is that, to swap two values, I can either

1) swapping two values stored in vars
2) swapping values' pointers

For example, I have two vars, a and b. Pointers to a and b are ffda and ffdc (in my local machine).

Innitially, a with adr ffda has the value of 5; b with addr ffdc has the value of 10;
after swap1 function,  a with adr ffda has the value of 10; b with addr ffdc has the value of 5;

But swap2 does not work, I had though it will changes a's addr to ffdc, and b's to ffda. I made mistakes somewhere. Could you please help me ?

Thanks

#include <stdio.h>

// Wrong

void swap(int x,int y)
{
      int temp=x;
      x=y;
      y=temp;
}

//Swap: By swappings value presented by *x and *y

void swap1(int *x,int *y)
{
      int temp=*x;
      *x=*y;
      *y=temp;
}

//Swap: By swapping pointers of x and y

void swap2(int *x,int *y)
{
      int temp=&*x;
      &*x=&*y;
      &*y=temp;
}


main ()
{
      int a=5;
      int b=10;

      printf("Before swap, a=%d,b=%d\n",a,b);
      printf("Before swap, address of a=%x,b=%x\n",&a,&b);

      swap(a,b);
      printf("After simple swap, a=%d,b=%d\n",a,b);
      printf("After simple swap, address of a=%x,b=%x\n",&a,&b);

      swap1(&a,&b);
      printf("After simple swap, a=%d,b=%d\n",a,b);
      printf("After simple swap, address of a=%x,b=%x\n",&a,&b);.

      swap2(&a,&b);
      printf("After simple swap 2, a=%d,b=%d\n",a,b);
      printf("After simple swap 2, address of a=%x,b=%x\n",&a,&b);
}