729.py

class Node:
    def __init__(self,s,e):
        self.e = e
        self.s = s
        self.left = None
        self.right = None
class MyCalendar:

    def __init__(self):
        self.root = None

    def book_helper(self,s,e,node):
        if s>=node.e:
            if node.right: return self.book_helper(s,e,node.right)
            else:
                node.right = Node(s,e)
                return True
        elif e<=node.s:
            if node.left: return self.book_helper(s,e,node.left)
            else:
                node.left = Node(s,e)
                return True
        else: return False
    def book(self, start, end):
        """
        :type start: int
        :type end: int
        :rtype: bool
        """
        if not self.root:
            self.root = Node(start,end)
            return True
        return self.book_helper(start,end,self.root)


# Your MyCalendar object will be instantiated and called as such:
# obj = MyCalendar()
# param_1 = obj.book(start,end)