swap two numbers without using third variable in c code example

Example 1: c program to swap two numbers using call by reference

#include <stdio.h>
 
void swap(int*, int*);
 
int main()
{
   int x, y;
 
   printf("Enter the value of x and y\n");
   scanf("%d%d",&x,&y);
 
   printf("Before Swapping\nx = %d\ny = %d\n", x, y);
 
   swap(&x, &y); 
 
   printf("After Swapping\nx = %d\ny = %d\n", x, y);
 
   return 0;
}
 
void swap(int *a, int *b)
{
   int temp;
 
   temp = *b;
   *b = *a;
   *a = temp;   
}

Example 2: c program for swapping of two numbers using temporary variable

#include <stdio.h>
int main()
{
    int a, b, temp;
    printf("enter the values of a and b: \n");
    scanf("%d%d", &a, &b );
    printf("current values are:\n a=%d\n b=%d\n", a, b);
    temp=a;
    a=b;
    b=temp;
    printf("After swapping:\n a=%d\n b=%d\n", a, b);
}