Compilare: main.cpp: In member function 'void qrollback::rollback()': main.cpp:89:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<upd>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 89 | for(int i=0;i<q.size();i++) | ~^~~~~~~~~ main.cpp:94:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<upd>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 94 | for(int i=0;i<q.size();i++) | ~^~~~~~~~~