how to swap values in variables in c

1#include <stdio.h>
2#include <stdlib.h>
3
4int main()
5{
6  	//initialize variables
7	int num1 = 10;
8	int num2 = 9;
9  	int tmp;
10  	
11  	//create the variables needed to store the address of the variables
12  	//that we want to swap values
13  	int *p_num1 = &num1;
14  	int *p_num2 = &num2;
15  
16  	//print what the values are before the swap
17  	printf("num1: %i\n", num1);
18    printf("num2: %i\n", num2);
19  
20  	//store one of the variables in tmp so we can access it later
21  	//gives the value we stored in another variable the new value
22  	//give the other variable the value of tmp
23  	tmp = num1;
24  	*p_num1 = num2;
25  	*p_num2 = tmp;
26
27  	//print the values after swap has occured
28   	printf("num1: %i\n", num1);
29    printf("num2: %i\n", num2);
30  	
31	return 0;
32}
33