Compilare: main.cpp: In function 'void Poligon()': main.cpp:82:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < p1.size() - 1;++i) ~~^~~~~~~~~~~~~~~ main.cpp:88:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0;j < p2.size() - 1;++j) ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void calculate_area()': main.cpp:130:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<p.size();++i) ~^~~~~~~~~ main.cpp:137:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < p.size() - 1;++i) ~~^~~~~~~~~~~~~~