Compilare: main.cpp: In function 'int variabila(const std::string&, int&)': main.cpp:68:29: warning: array subscript has type 'char' [-Wchar-subscripts] 68 | return fr[s[p-1]]; | ^ main.cpp: In function 'int main()': main.cpp:75:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 75 | for(int i=0; i<=x.size(); i++) | ~^~~~~~~~~~ main.cpp:80:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | for(int i=0; i<val.size(); i++) | ~^~~~~~~~~~~ main.cpp:82:21: warning: array subscript has type 'char' [-Wchar-subscripts] 82 | if(fr[val[i]] == 0) | ^ main.cpp:83:22: warning: array subscript has type 'char' [-Wchar-subscripts] 83 | fr[val[i]] = 1; | ^ main.cpp:85:22: warning: array subscript has type 'char' [-Wchar-subscripts] 85 | fr[val[i]] = 0; | ^