Eroare de compilare: user.cpp:13:1: error: reference to ‘unordered_set’ is ambiguous unordered_set<int> hash1; ^ user.cpp:12:9: note: candidates are: template<class Key, class Hash, class KeyEqual, class Allocator> class unordered_set > class unordered_set; ^ In file included from /usr/include/c++/4.8/unordered_set:48:0, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:116, from user.cpp:1: /usr/include/c++/4.8/bits/unordered_set.h:93:11: note: template<class _Value, class _Hash, class _Pred, class _Alloc> class std::unordered_set class unordered_set : __check_copy_constructible<_Alloc> ^ user.cpp:13:1: error: ‘unordered_set’ does not name a type unordered_set<int> hash1; ^ user.cpp: In function ‘int main()’: user.cpp:33:13: error: ‘hash1’ was not declared in this scope hash1.insert(a1 * i * i * i * ct + a2 * j * j * j * ct); ^ user.cpp:39:26: error: ‘hash1’ was not declared in this scope sol+=hash1.count(a3 * i * i * i + a4 * j * j * j + a5 * k * k * k); ^