Which is better?

Question

1. using namespace std
2. Write the std manually (std::cout , std::cin)
3. Write using std::cout , using std::cin before int main()?

Answer 1

https://code.sololearn.com/c61v1WUGFXoK/?ref=app

that is why number 1 is called as bad practice
But anyway
Everybody care output more than code,right?

Answer 2

https://www.sololearn.com/Discuss/294730/?ref=app

Answer 3

Ummmm sound like 2 equal 3 😑
then ans is only 1 and 2
Ans is 2

Well if you define 2 methods inside your own namespaces that have same name but different namespace

ex namespace: foo(QUXX) bar(QUXX)
If you type using namespace foo and bar

then you call QUXX()....
lemme make example code