Compilare: user.cpp: In function ‘void solve()’: user.cpp:24:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[y].size();i++) ^ user.cpp:30:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<a[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:81:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (q<sol[i].size()) ^