Main.cc:3:1: error: ‘priority_queue’ does not name a type priority_queuepq; ^~~~~~~~~~~~~~ Main.cc: In function ‘int main()’: Main.cc:6:5: error: ‘cin’ was not declared in this scope cin>>n; ^~~ Main.cc:6:5: note: suggested alternative: In file included from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:75:0, from Main.cc:2: /usr/include/c++/7/iostream:60:18: note: ‘std::cin’ extern istream cin; /// Linked to standard input ^~~ Main.cc:10:9: error: ‘pq’ was not declared in this scope pq.push(a);pq.push(a-b); ^~ Main.cc:12:15: error: ‘pq’ was not declared in this scope int ans = pq.top(); ^~ Main.cc:14:5: error: ‘cout’ was not declared in this scope cout<& __os) ^~~~