volei.cpp: In function `int main()': volei.cpp:135: warning: unused variable `int l1' volei.cpp:135: warning: unused variable `int l2' volei.cpp:135: warning: unused variable `int lenx' volei.cpp:135: warning: unused variable `int leny' volei.cpp:136: warning: unused variable `Point x[50]' volei.cpp:136: warning: unused variable `Point y[50]' volei.cpp: In function `void Convex_Hull(Point*, int, Point*, int&)': volei.cpp:35: warning: `int sign' might be used uninitialized in this function