Compilare: user.cpp: In function ‘bool get_val(std::string)’: user.cpp:29:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] r=!val[s[i]]; ^ user.cpp:35:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] r=val[s[i]]; ^ user.cpp: In function ‘bool get_or(std::string)’: user.cpp:49:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size() && s[i]=='|') ^ user.cpp: In function ‘bool get_xor(std::string)’: user.cpp:59:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size() && s[i]=='^') ^ user.cpp: In function ‘bool eval(std::string)’: user.cpp:69:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size() && s[i]=='&') ^ user.cpp: In function ‘int main()’: user.cpp:83:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<max(s1.size(),s2.size());++i) ^ user.cpp:85:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s1.size() && isalpha(s1[i]) && !fol[s1[i]]) ^ user.cpp:85:59: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(i<s1.size() && isalpha(s1[i]) && !fol[s1[i]]) ^ user.cpp:88:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] fol[s1[i]]=1; ^ user.cpp:90:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s2.size() && isalpha(s2[i]) && !fol[s2[i]]) ^ user.cpp:90:59: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(i<s2.size() && isalpha(s2[i]) && !fol[s2[i]]) ^ user.cpp:93:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] fol[s2[i]]=1; ^ user.cpp:99:61: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(int j=0;j<=cnt;++j)if((1<<j) & per)val[mp[j]]=1; ^