how to swap values of two variables in c?

Question

how many types we can swap values of two variables without using third variable?

Answer 1

Just going the logic -
Assume you have two variable a and b and you want to swap the value of a and b then try the following logic -

a=a+b;
b=a-b;
a=a-b;

Dry run assume a=5 and b =10
a=a+b means a=15 b=10
b=a-b means a=15 b=5
a=a-b means a=10 b=5