Compilare: user.cpp: In function ‘bool e_operatie(int)’: user.cpp:29:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i + 1 >= S.size()) return 0; ^ user.cpp: In function ‘void adaug(char, int&)’: user.cpp:36:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < aux.size() && isupper(aux[i])) op += aux[i++]; ^ user.cpp: In function ‘void fa_string_bun()’: user.cpp:47:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < aux.size() ; ++i) { ^ user.cpp: In function ‘void fa_curr_op(int&)’: user.cpp:60:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!operatii.empty() && prio[ch] <= prio[operatii.top()]) ^ user.cpp:60:63: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!operatii.empty() && prio[ch] <= prio[operatii.top()]) ^ user.cpp: In function ‘void makePolish()’: user.cpp:74:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i < S.size(); ++i) { ^ user.cpp: In function ‘bool eval()’: user.cpp:112:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < vec_aux.size(); ++i) { ^ user.cpp:115:62: warning: array subscript has type ‘char’ [-Wchar-subscripts] else if(isupper(ch) || islower(ch)) numere.push(val[ch]); ^ user.cpp: In function ‘int main()’: user.cpp:131:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[variabile[i]] ^= 1; ^