二叉树问题---打印二叉树的边界节点

问题：
给定一棵二叉树的头节点，按照如下两种标准分别实现二叉树边界节点的逆时针打印。

标准一：

1.头节点为边界节点
2.叶节点为边界节点
3.如果节点在其所在层中的最左边或最右边，那么也是边界节点

标准二：

1.头节点为边界节点
2.叶节点为边界节点
3.树左边界延伸下去的路径为边界节点
4.树右边界延伸下去的路径为边界节点

#标准一
def printEdge1(root):
    def getHeight(root, height=0):
        if not root:
            return 0
        return max(getHeight(root.left, height+1), getHeight(root.right, height+1)) + 1

    def getMap(root, i, map):
        if not root:
            return
        if map[i][0] == None:
            map[i][0] = root
        map[i][1] = root
        getMap(root.left, i+1, map)
        getMap(root.right, i+1, map)

    def printLeafNotInMap(root, i, map):
        if not root:
            return
        if not root.left and not root.right and root != map[i][0] and \
                root != map[i][1]:
            print(root.val, end=' ')
        printLeafNotInMap(root.left, i+1, map)
        printLeafNotInMap(root.right, i+1, map)

    if not root:
        return
    height = getHeight(root)
    map = [[None for i in range(2)] for j in range(height)]
    getMap(root, 0, map)
    for i in range(len(map)):
        print(map[i][0].val, end=' ')
    printLeafNotInMap(root, 0, map)
    for i in range(len(map)-1, -1, -1):
        if map[i][0] != map[i][1]:
            print(map[i][1].val, end=' ')


#标准二
def printEdge2(root):
    def printLeft(root, isPrint):
        if not root:
            return
        if isPrint or (root.left == None and root.right == None):
            print(root.val, end=' ')
        printLeft(root.left, isPrint)
        printLeft(root.right, bool(isPrint and root.left == None))

    def printRight(root, isPrint):
        if not root:
            return
        printRight(root.left, bool(isPrint and root.right == None))
        printRight(root.right, isPrint)
        if isPrint or (root.left == None and root.right == None):
            print(root.val, end=' ')


    if not root:
        return
    print(root.val, end=' ')
    if root.left and root.right:
        printLeft(root.left, True)
        printRight(root.right, True)
    elif root.left:
        printEdge2(root.left)
    elif root.right:
        printEdge2(root.right)