Compilare: main.cpp: In function 'void poligon()': main.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<p.size()-1;++i) ~^~~~~~~~~~~ main.cpp: In function 'void points_on_poligon()': main.cpp:53:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < p.size() - 1;++i) ~~^~~~~~~~~~~~~~