Compilare: main.cpp: In function 'int solve(int, int, std::string)': main.cpp:13:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int i = 0; i < s.size(); i ++){ | ~~^~~~~~~~~~ main.cpp:19:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | while(i < s.size() && s[i] >= '0' && s[i] <= '9'){ | ~~^~~~~~~~~~ main.cpp:26:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | while(i < s.size() && s[i] >= '0' && s[i] <= '9'){ | ~~^~~~~~~~~~ main.cpp:12:10: warning: unused variable 'semn' [-Wunused-variable] 12 | char semn = '+'; | ^~~~