Init initializes or clears list l.

removes the head and returns its value

Remove the top element from the stack and return it's value If the stack is empty, return nil

PushFront inserts a new Node with value v at the front of list l

Remove removes e from l if e is an element of list l. It returns the element value e.Value.

Walker launches Walk in a new goroutine, and returns a read-only channel of values.

O(n) time with O(1) space by overwriting one of the original lists.

Return a sorted list with the Boxes that build the highest Stack.

Check whether the pixel (x, y) falls within the Screen.