Compilare: main.cpp: In function 'void reverse_p(std::vector<point>&)': main.cpp:53:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < p.size() / 2;++i) ~~^~~~~~~~~~~~~~ main.cpp: In function 'bool exist(std::vector<point>&, point)': main.cpp:91:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<p.size();++i) ~^~~~~~~~~ main.cpp: In function 'void Determine()': main.cpp:100:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < p1.size() - 1; ++i) ~~^~~~~~~~~~~~~~~ main.cpp:104:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; j < p2.size() - 1; ++j) ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void calculate_area()': main.cpp:144:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<p.size()-1;++i) ~^~~~~~~~~~~