Why all the compilers of C# in android doesn't are how the guides teach?

Question

Do you have noted that all the compilers in android use:
"#include <stdio.h>"

But all the guides (how... SoloLearn xD) teach:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
etc.

Do you know one compiler offline that use this syntax?

Answer 1

That is very... well, I don't have comments xd.

Then the android applications are incorrect too

Answer 2

Toda la Play Store y fuera de la Play Store, reciben el nombre de C # pero usan C

Answer 3

Applications like C4droid

There are many that I have tried and they have very common names (like "C# compiler" simply)

The only one that has worked (besides SoloLearn has been DCoder, but it needs an internet connection :c

Answer 4

I realized and I understood it a moment ago :c

Answer 5

thank you

Answer 6

Use Xamarin. Much better.

Answer 7

Well, then I will continue work only in my PC