Compilare: user.cpp: In function ‘bool comparePoints(Point, Point)’: user.cpp:19:32: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] return a.y<b.y || a.y==b.y && a.x<b.x; ^ user.cpp: In function ‘void convexHull()’: user.cpp:44:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < a.size(); i++) { ^ user.cpp: In function ‘void writeData()’: user.cpp:55:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < h.size(); i++) { ^