Compilare: user.cpp: In function ‘void mul(char*, char)’: user.cpp:52:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = ((t += A[i] * B) % 10); ^ user.cpp:52:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = ((t += A[i] * B) % 10); ^ user.cpp: In function ‘void div(char*, char)’: user.cpp:63:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = (t = t * 10 + A[i])/ B; ^ user.cpp:63:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = (t = t * 10 + A[i])/ B; ^ user.cpp:65:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(;A[0] > 1 && ! A[A[0]]; A[0]--); ^ user.cpp: In function ‘void add(char*, char)’: user.cpp:74:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = ((t += A[i]) % 10); ^ user.cpp:74:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[i] = ((t += A[i]) % 10); ^ user.cpp: In function ‘void fromBinary(char*, std::string&)’: user.cpp:103:24: warning: argument to ‘sizeof’ in ‘void* memset(void*, int, size_t)’ call is the same expression as the destination; did you mean to provide an explicit length? [-Wsizeof-pointer-memaccess] memset(A, 0, sizeof(A)); ^ user.cpp:104:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(char i = 0; i < S.length(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:158:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < X.length() && i < Y.length()) ^ user.cpp:158:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < X.length() && i < Y.length()) ^