Meaning of #define ll

#1

what is written in the first line #define ll long long and how does it affect the code

#2

Hey @vector.9974
#define ll long long is a macro
What it does is ,wherever u have written ll in your code then it will replace it by long long in compilation time .
You can say its an alternate to typedef above.

It can also be USed to define constants or functions like
#defne pi 3.14
#define maximum(a,b) ((a>b)?a:b)

etc…