Compilare: main.cpp: In function 'void citire()': main.cpp:121:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 121 | for ( int i = 0 ; i < apel.size() ; i++ ) | ~~^~~~~~~~~~~~~ main.cpp:128:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 128 | for ( int i = 1 ; i <= se.size() ; i++ ) | ~~^~~~~~~~~~~~ main.cpp:139:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 139 | for ( int i = 1 ; i <= semare.size() ; i++ ) | ~~^~~~~~~~~~~~~~~~