Path to given node

Check out the problem description here.

Path to Given Node - InterviewBit

Solution

class Solution:
    def solve(self, A, B):
        ds=[]
        self.rec(A,B,ds)
        return ds
    def rec(self,root,B,ds):
        if root ==None :
            return False
        ds.append(root.val)
        if root.val == B:
            return True
        if self.rec(root.left,B,ds) or self.rec(root.right,B,ds):
            return True
        ds.pop(-1)
        return False

Time :O(N)

Space :O(h) height of the tree