根据前序序列求根结点，根据中序序列求左右子树。

如上图：根据前序序列，谁在前面谁就是根结点；根据根结点，确定左右子树。

class BiTreeNode:def __init__(self, data):self.data = dataself.lchild = Noneself.rchild = Noneclass SolvedPostOrder:def __init__(self, pre_order, in_order):self.pre_order = pre_orderself.in_order = in_orderdef soled_post_order(self, pre_order, in_order):if not pre_order:return Noneelse:root = BiTreeNode(pre_order[0])in_order_root_pos = in_order.index(pre_order[0])root.lchild = self.soled_post_order(pre_order[1:in_order_root_pos+1], in_order[0:in_order_root_pos])root.rchild = self.soled_post_order(pre_order[in_order_root_pos+1:], in_order[in_order_root_pos+1:])return rootdef post_order(self, root):# 后序排列if root:self.post_order(root.lchild)self.post_order(root.rchild)print(root.data, end='')def __call__(self):root = self.soled_post_order(self.pre_order, self.in_order)self.post_order(root)while True:pre_order = input()in_order = input()# pre_order = 'ABCDEFG'# in_order = 'DCBAEFG'post_order = SolvedPostOrder(pre_order, in_order)post_order()print()