Compilare: user.cpp: In function ‘void Solve()’: user.cpp:53:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();++i) ^ user.cpp:57:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(S[i]>='0'&& S[i]<='9' && i<S.size())val=val*10+(S[i]-'0'),++i; ^ user.cpp: In function ‘int main()’: user.cpp:84:13: warning: statement is a reference, not call, to function ‘init’ [-Waddress] init; ^ user.cpp:84:13: warning: statement has no effect [-Wunused-value]