Compilare: user.cpp: In function 'void back(char, char, double)': user.cpp:16: warning: array subscript has type 'char' user.cpp: In function 'int main()': user.cpp:24: warning: format '%d' expects type 'int*', but argument 2 has type 'char*' user.cpp:24: warning: format '%d' expects type 'int*', but argument 3 has type 'char*' user.cpp:25: warning: array subscript has type 'char' user.cpp:31: warning: array subscript has type 'char'