Compilare: user.cpp: In function ‘int main()’: user.cpp:94:24: warning: unused variable ‘del’ [-Wunused-variable] long long prev = 0,del; ^ user.cpp: In instantiation of ‘void heap<T>::down_heap(int) [with T = std::pair<long long int, int>]’: user.cpp:38:20: required from ‘void heap<T>::pop() [with T = std::pair<long long int, int>]’ user.cpp:97:29: required from here user.cpp:51:13: warning: variable ‘left’ set but not used [-Wunused-but-set-variable] int left,right,chosen; ^