HHW Q20. WAP to swap 2 nos. without using third variable .

#include<iostream.h>
#include<conio.h>
void main()
{
clrscr();
int a,b;
cout<<"Enter first no. a = ";
cin>>a;
cout<<"Enter second no. b = ";
cin>>b;
a=a+b;
b=a-b;
a=a-b;
cout<<"a = "<<a<<"\n"<<"b = "<<b;
getch();
}