Question

#include int main() { a=5; b=10; a=a+b-(b=a); printf("\na= %d b= %d",a,b); } this program is swapping of two variables... how does it work???

Answer 1

look at the math.
a=5
b=10
then, the math does:
a=(5)+(10)-(10-5)=10
a->b=10

Answer 2

working-
first your 'a' value will be stored in 'b' as yu had mention b=a which is assignment operator.....then a=a+b-(b=a) which makes 'a' value assigned with 'b'
tracing-
a=5
b=10
a=a+b-(b=a)
a=5+10-(b=5)
a=15-5
a=10

hence a=10 and b=5