beginner

Hello Coders! I'm looking for help swapping variables with C++, I know that you can use a temporary variable but you can also do it without it. Can someone show me both ways? int a = 5; int b = 10; //I want A to 10 and B to be 5. // I think I have an idea, is this correct? a=a+b; b=b-a

Hi guys, I'm currently learning C++ and I'm kinda wondering what I should build to practice my C++. I know it shouldn't be too complex or I'll never finish it but I'm not sure what to build, I was thinking of a calculator or even a notepad but would that be too much? Any ideas?