Compilare: main.cpp: In function 'int main()': main.cpp:469:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 469 | for (int i = 2; i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp:481:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 481 | for (int i = 0; i < b.size(); ++i) | ~~^~~~~~~~~~ main.cpp:491:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 491 | if (k == a.size() - 1) | ~~^~~~~~~~~~~~~~~