Eroare de compilare: user.cpp: In function ‘void Solve()’: user.cpp:35:28: error: ‘ok’ was not declared in this scope if(v[i].val>=0 && !ok)ok=1; ^ user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();++i) ^ user.cpp:46:57: 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; ^