C ++ question

Question

#include <iostream>
using namespace std;
int x=20;
int f(){
x-=2;
return --x;
}
int g(){
int x=50;
x++;
return f();
}
int main() {
while(x%3>=1)
cout<<g()<<" ";
return 0;
}

Can someone tell me how this is work?
I know the answer but not how it’s work

Answer 1

start with " while " loop
>>while(20%3>=1) //true
>>calls " g() " function
>>g() calls " f() " //x in g() set to x=51 , I think no work of this x
>>in f() value of " x " is 20 //x is declared global (not in f() )
>>in f() x=x-2; > x=20-2; x=18
>>return --x //it makes x=17 and it return to g() , g() return in main and 17 will be printed
>>now value of global variable is x=17
>>again start with while loop while(17%3>=1) //same process till while condition evaluates to false !

HOPE THIS HELP !

I suggest, if you are beginner, write this process on your notebook