Compilare: user.cpp: In function ‘void convex_hull()’: user.cpp:57:12: warning: unused variable ‘p’ [-Wunused-variable] int i, p, Head; ^ user.cpp: In function ‘void Convex_hull()’: user.cpp:75:12: warning: unused variable ‘p’ [-Wunused-variable] int i, p, Head; ^ user.cpp: In function ‘void readPolygon()’: user.cpp:94:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:96:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v[i].x, &v[i].y); ^ user.cpp: In function ‘double minAreaRect()’: user.cpp:113:21: warning: ‘p3’ may be used uninitialized in this function [-Wmaybe-uninitialized] int p1 = 1, p2, p3; ^