Compilare: main.cpp: In function 'bool comp(std::__cxx11::string, std::__cxx11::string)': main.cpp:16:16: warning: array subscript has type 'char' [-Wchar-subscripts] if(val[a[k]]>val[b[k]]) return false; ^ main.cpp:16:26: warning: array subscript has type 'char' [-Wchar-subscripts] if(val[a[k]]>val[b[k]]) return false; ^ main.cpp:17:21: warning: array subscript has type 'char' [-Wchar-subscripts] else if(val[a[k]]<val[b[k]]) return true; ^ main.cpp:17:31: warning: array subscript has type 'char' [-Wchar-subscripts] else if(val[a[k]]<val[b[k]]) return true; ^ main.cpp: In function 'int main()': main.cpp:26:10: warning: array subscript has type 'char' [-Wchar-subscripts] val[c]=i; ^