Inorder successor predecessor in BST

'''
vvv imp
while finding inorder predecessor if you are at target node then still you have to continue to left to check whether any element exists whose value is less than target and update it with predecessor
'''
class Solution:
    """
    @param root: the given BST
    @param p: the given node
    @return: the in-order predecessor of the given node in the BST
    """
    def inorderPredecessor(self, root, p):
        cur=root
        pre=None
        while cur:
            if p.val<=cur.val:
                cur=cur.left
            else:
                pre=cur
                cur=cur.right
        return pre
'''
while finding inorder successor if you are at target node then still you have to continue to left to check whether any element exists whose value is less than target and update it with successor
'''

class Solution:
    """
    @param: root: The root of the BST.
    @param: p: You need find the successor node of p.
    @return: Successor of p.
    """
    def inorderSuccessor(self, root, p):
        succ=None
        cur=root
        while cur:
            if p.val<cur.val:
                succ=cur
                cur=cur.left
            else:
                cur=cur.right
        return succ