Macros or also known as #define in c++ are very useful, but it takes a while to think of some great one that will save you a LOT of time, or a little, but it still makes it look better. Like, I was a python programmer and then when I switched to c++, I wasn't used to writing string, so I made a define like this:

#define str string

Here are my personal macros

#define sz size
#define yes cout << "YES"
#define no cout << "NO"
#define str string
#define ll long long
#define ull unsigned ll
#define uint unsigned int
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define vc vector
#define vci vector<int>
#define vcstr vector<str>
#define vcll vector<ll>
#define vcc vector<char>
#define fast ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define fi first
#define se second
#define be begin()
#define en end()

When you start solving a problem, you usually write long pieces of code. #define allows you to shorten and simplifie any ones code. If you want to make a macro for yourself you need to know how to make one first:

// here  we make a define for long long:
#define ll long long

After you do that you can use it anytime you want, for example:

ll a = 98210;

vector<ll> t;

unsigned ll factorial(x) {

if (x == 1 || x == 0) return 1;

else return x * factorial(x - 1);

}

Remember, defines vary from people, you can even get inspired by other peoples #define's too! ask a friend about his defines, they might also be useful for you too!

Everyone wants to make there code FASTER but there is lots of simple solution. the first and most simple one is this:

std::ios::sync_with_stdio(false);

What this does is that usually cout is synced with stdio. so if we set it to false it will make the code slightly faster

Also you can set cin.tie and cout.tie to NULL like this:

cin.tie(NULL);
cout.tie(NULL);

Which will also make it alittle bit faster.