Compilare: main.cpp: In function 'int solve(std::string)': main.cpp:38:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | for(int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~ main.cpp:50:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | while(i < s.length() && isdigit(s[i])) | ~~^~~~~~~~~~~~ main.cpp: In function 'int calcul(int, int, char)': main.cpp:30:1: warning: control reaches end of non-void function [-Wreturn-type] 30 | } | ^