func (l *List) PushFront(v int) *Element {
	e := &Element{v, l.head}
	l.head = e
	if l.N == 0 {
		l.tail = e
	}
	l.N++
	return e
}
//PushFront inserts a new element e with value v at the front of list l and returns e.

PushFront inserts a new element e with value v at the front of list l and returns e.
// PushFront inserts a new element e with value v at the front of list l and returns e .
func (l *List) PushFront(v int) *Element {
	e := &Element{v, l.head}
	l.head = e
	if l.N == 0 {
		l.tail = e
	}
	l.N++
	return e
}
func ( l * List ) PushFront ( v int ) * Element { e := & Element { v , l . head } l . head = e if l . N == 0 { l . tail = e } l . N ++ return e }
PushFront inserts a new element e with value v at the front of list l and returns e.
PushFront inserts a new element e with value v at the front of list l and returns e .