Compilare: user.cpp: In function ‘int Evaluate()’: user.cpp:43:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ^ user.cpp:64:48: warning: array subscript has type ‘char’ [-Wchar-subscripts] num.push(x[S[i]]); ^ user.cpp: In function ‘int main()’: user.cpp:81:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ^ user.cpp:104:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] x[k]=!x[k]; ^ user.cpp:104:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] x[k]=!x[k]; ^