Given inorder and postorder traversal of a tree, construct the binary tree.

BINARYTREE1.py

__author__ = 'Vivek'

#Given inorder and postorder traversal of a tree, construct the binary tree.

# Definition for a  binary tree node
class TreeNode:
     def __init__(self, x):
         self.val = x
         self.left = None
         self.right = None

class Solution:
    # @param inorder : list of integers denoting inorder traversal
    # @param postorder : list of integers denoting postorder traversal
    # @return the root node in the tree
    def buildTree(self, inorder, postorder):
        #print inorder, postorder
        if len(inorder) == 0 and len(postorder) == 0:
            return None
        else :
            val = postorder[len(postorder)-1]
            root = TreeNode(val)
            i = inorder.index(val)
            #print i
            root.left = self.buildTree(inorder[ : i], postorder[ : i])
            root.right = self.buildTree(inorder[i+1 :], postorder[i : -1])
            return root