func (s *VecStack) PeekN(n int) []*Vec {
	var (
		N   []*Vec
		cur *item
	)
	N = make([]*Vec, 0, n)
	cur = s.top
	for len(N) < n {
		if cur == nil {
			break
		}
		N = append(N, cur.value)
		cur = cur.next
	}
	return N
}
func (s *VecStack) PeekN(n int) []*Vec {
	var (
		N   []*Vec
		cur *item
	)
	N = make([]*Vec, 0, n)
	cur = s.top
	for len(N) < n {
		if cur == nil {
			break
		}
		N = append(N, cur.value)
		cur = cur.next
	}
	return N
}
func ( s * VecStack ) PeekN ( n int ) [ ] * Vec { var ( N [ ] * Vec cur * item ) N = make ( [ ] * Vec , 0 , n ) cur = s . top for len ( N ) < n { if cur == nil { break } N = append ( N , cur . value ) cur = cur . next } return N }
// PeekN returns at max the N topmost item without removing them from the stack.
PeekN returns at max the N topmost item without removing them from the stack .