Compilare: user.cpp: In function ‘void parse(int&)’: user.cpp:38:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;i<v.size() && isDigit(v[i]);++i){ ^ user.cpp: In function ‘void makePol()’: user.cpp:56:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v.size();++i){ ^ user.cpp: In function ‘int calc(int, int, int)’: user.cpp:16:1: warning: control reaches end of non-void function [-Wreturn-type] } ^