Write a C program to interchange two numbers and display the interchanged numbers.

C program to swap two numbers using third variable.

#include<stdio.h>
int main()
{
   int x, y, temp;
   printf("Enter the value of x and y\n");
   scanf("%d%d", &x, &y);
   printf("Before Swapping\nx = %d\ny = %d\n",x,y);
   temp = x;
   x    = y;
   y    = temp;
   printf("After Swapping\nx = %d\ny = %d\n",x,y);
   return 0;
}
OR
Let's see a simple c example to swap two numbers without using third variable.
#include<stdio.h>  
int main()    
{    
int a=10, b=20;      
printf("Before swap a=%d b=%d",a,b);      
a=a+b;//a=30 (10+20)    
b=a-b;//b=10 (30-20)    
a=a-b;//a=20 (30-10)    
printf("\nAfter swap a=%d b=%d",a,b);    
return 0;  
}