Compilare: user.cpp: In function ‘void goPolnish()’: user.cpp:44:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(rankOp[S.top()] >= rankOp[s[i]]){ ^ user.cpp:44:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(rankOp[S.top()] >= rankOp[s[i]]){ ^ user.cpp: In function ‘int main()’: user.cpp:72:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.in","r",stdin); ^ user.cpp:73:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.out","w",stdout); ^ user.cpp:77:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",s+1); ^