how to find the height of a node in binary tree recursively

Question

path = 0 # the lenght of the path
    while self.right != None or self.left != None:
        while self.right != None:
            self = self.right
            path = path +1 
        while self.left != None:
            self = self.left
            path = path +1
    return path

this is my sample code for find the Height, is defined as the length of the longest path by number of nodes from self to a leaf. The height of a leaf node is 1.

it doesn't work.

Answer 1

Here is the complete program in Python ::

class Node :
    def __init__(self, data):
        self.data = data
        self.left = None
        self.right = None

def maxDepth(node):
    if node is None :
        return 0
    else :
        ldepth = maxDepth(node.left)
        rdepth = maxDepth(node.right)

        if (ldepth>rdepth):
            return ldepth +1
        else :
            return rdepth +1

root = Node(1)
root.left = Node(2)
root.right = Node(3)
root.left.left = Node(4)
root.left.right = Node(5)


print "Height of tree is %d" %(maxDepth(root))

Source : here