C Program to Swap Two Numbers without using Third Variable

C Program to Swap Two Numbers using Temporary Variables:

#include<stdio.h>
#include<conio.h>
void main()
{
int x,y, temp;
clrscr();
printf("Enter the value of x :");
scanf("%d",&x);
printf("Enter the value of y :");
scanf("%d",&y);
temp=x;
x=y;
y=temp;
printf("\nThe value of x =%d",x);
printf("\nThe value of y =%d",y);
getch();
}

Output :
Enter the value of x :25
Enter the value of y :30

The value of x =30
The value of y =25

C Program to Swap Two Numbers Without using Temporary Variables :

#include<stdio.h>
#include<conio.h>
void main()
{
int a,b;
clrscr();
printf("Enter the value of a :");
scanf("%d",&a);
printf("Enter the value of b :");
scanf("%d",&b);
a=a+b;
b=a-b;
a=a-b;
printf("After swapping: a=%d,b=%d",a,b);
getch();
}

Output :
Enter the value of a :15
Enter the value of b :10

After swapping: a=10,b=15