Compilare: user.cpp: In function ‘long long int factor()’: user.cpp:67:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[p]>='A' && s[p]<='Z' && p<s.size()) ^ user.cpp:73:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[p]!=')' && p<s.size()) ^ user.cpp:83:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(s[p]>='a' && s[p]<='z' && p<s.size()) ^ user.cpp:90:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[p]>='0' && s[p]<='9' && p<s.size()) ^ user.cpp: In function ‘int main()’: user.cpp:120:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<expresie[i].size()) ^