Eroare de compilare: main.cpp: In function 'void solve()': main.cpp:23:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | for(int i=0;i<a.size();i++) { | ~^~~~~~~~~ main.cpp:27:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | for(int i=0;i<a.size();i++) { | ~^~~~~~~~~ main.cpp:40:25: error: 'max_element' was not declared in this scope 40 | if(stk.empty() || (*max_element(fr_b.begin(),fr_b.end()))>0) { | ^~~~~~~~~~~ Non zero exit status: 1