4.重建二叉树(python)

根据前序和中序重建二叉树：

class Solution:
    # 返回构造的TreeNode根节点
    def reConstructBinaryTree(self, pre, tin):
        # write code here
        if len(pre)==0:
            return None
        if len(pre) == 1:
            return TreeNode(pre[0])
        root = TreeNode(pre[0])
        tinL = tin[0:tin.index(pre[0])]

        tinR = tin[tin.index(pre[0])+1:]
        root.left = self.reConstructBinaryTree(pre[1:tin.index(pre[0])+1],tinL)
        root.right = self.reConstructBinaryTree(pre[tin.index(pre[0])+1:],tinR)
        return root

2019-12-31 12:43:06