Build the tree recursively

```
class Solution(object):
def buildTreeT(self, inorder, postorder, s1, e1, s2, e2):
if e2-s2 <= 0:
return None
node = TreeNode(postorder[e2-1])
i = s1
while i < e1:
if inorder[i] == node.val:
break
i += 1
node.left = self.buildTreeT(inorder, postorder, s1, i, s2, (s2+(i-s1)))
node.right = self.buildTreeT(inorder, postorder, i+1, e1, (s2+(i-s1)), e2-1)
return node
def buildTree(self, inorder, postorder):
return self.buildTreeT(inorder, postorder, 0, len(inorder), 0, len(postorder))
```