Lmao are you fucking kidding me. You say like two words about your solution. Do you even expect someone to answer?

Your code is filled with crappy shorthands which are impossible to parse for anyone else. What is more, your code is not even indented properly.

How do you even think someone is going to parse what you might mean by

bool cmp(pair<int,pair<int,int> > a,pair<int,pair<int,int> > b){
    if(a.se.se==b.se.se && a.se.fi!=b.se.fi) return a.se.fi<b.se.fi;
    if(a.se.fi==b.se.fi) return a.fi<b.fi;
    return a.se.se<b.se.se;
}

or maybe

a.fi=pts[0].fi;
a.se.se=pts[0].se.se;
a.se.fi=pts[0].se.fi;
 
b.fi=pts[n-1].fi;
b.se.se=pts[n-1].se.se;
b.se.fi=pts[n-1].se.fi;