Compilare: user.cpp: In function ‘bool comp(prod, prod)’: user.cpp:18:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ind<a.nume.size() && ind<b.nume.size()) ^ user.cpp:18:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ind<a.nume.size() && ind<b.nume.size()) ^ user.cpp:24:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ind==a.nume.size()) return 1; ^ user.cpp: In function ‘int main()’: user.cpp:31:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ^ user.cpp:38:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]<='z' && s[i]>='a' && i<s.size()) ^ user.cpp:43:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]==' ' && i<s.size()) ++i; ^ user.cpp:45:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]<='9' && s[i]>='0' && i<s.size()) ^ user.cpp:65:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]<='9' && s[i]>='0' && i<s.size()) ^