Compilare: user.cpp: In function ‘void Add(char*, char*)’: user.cpp:21: warning: array subscript has type ‘char’ user.cpp: In function ‘void Dif(char*, char*)’: user.cpp:33: warning: array subscript has type ‘char’ user.cpp: In function ‘int main()’: user.cpp:63: warning: array subscript has type ‘char’ user.cpp:50: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result