Can anyone explain?

Question

https://code.sololearn.com/ctYxerPj6ew6/?ref=app

one of the C++ challenges on here, hard coded it and tried to understand but can’t work out why it cout’s 10?? Not sure what c#.#.# etc is doing? Or what happens when the ={#,#,#,#} is called, help explaining is more than welcome. Cheers

Answer 1

im glad to help, to tell you the truth, the naming and ordering of the varibles got me confused for a bit there too

Answer 2

Thank you so much for the quick and detailed response. Never seen anything like that before and couldn’t understand what was going on at all. Kudos to you cheers, tried a few different combinations and starting to get it now 👌🏻

Answer 3

So we know that C is a structure, containig two differents structures, like this

struct C{
A a; B b;
};

To acess each member we use the following

C.a to get to the elements to the A struct
C.b to get to the elements to the B struct

We want now get to the variables, so we continue, t
he sintaxe its the same, since A and B are struct too

C.a.a
C.a.b
C.b.a
C.b.b

its important to know that each C struct will be put in the memory as declared:
so you have C{A a; B b} = C{int a, float b; int b, float a}

Now when the assigment its done:
C c1 ={1,2,3,4};
its the same as:
c1.a.a = 1
c1.a.b = 2
c1.b.b = 3
c1.b.a = 4

C c2 ={5,6,7,8};
its the same as:
c2.a.a = 5
c2.a.b = 6
c2.b.b = 7
c2.b.a = 8

so c1.b.a + c2.a.b = 4 + 6 = 10