Compilare: user.cpp: In function ‘int expresie()’: user.cpp:18:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] == '+' || S[i] == '-'){ ^ user.cpp:18:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] == '+' || S[i] == '-'){ ^ user.cpp:20:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(S[i] == '+'){ ^ user.cpp: In function ‘int termen()’: user.cpp:38:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] == '*' || S[i] == '/'){ ^ user.cpp:38:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] == '*' || S[i] == '/'){ ^ user.cpp:40:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(S[i] == '*'){ ^ user.cpp: In function ‘int factor()’: user.cpp:57:11: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(S[i] == '('){ ^ user.cpp:66:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] >= '0' && S[i] <= '9'){ ^ user.cpp:66:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i] >= '0' && S[i] <= '9'){ ^ user.cpp:67:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] sum = sum * 10 + (S[i] - '0'); ^ user.cpp: In function ‘int main()’: user.cpp:76:14: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] fin >> S + 1;i = 1; ^