Compilare: main.cpp: In function 'void check(int)': main.cpp:20:8: warning: operation on 'nxt' may be undefined [-Wsequence-point] nxt=(poz==n-1)?nxt=v[0]:nxt=v[poz+1]; main.cpp:21:8: warning: operation on 'prv' may be undefined [-Wsequence-point] prv=(!poz)?prv=v.back():prv=v[poz-1]; main.cpp: In function 'std::vector<std::complex<double> > PolygonCut(std::vector<std::complex<double> >&, Point, Point)': main.cpp:37:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0,j=a.size()-1;i<a.size();j=i++) ~^~~~~~~~~