Given a BST and its root, print all sequences of nodes which give rise to the same bst

Question

Given a BST, find all sequences of nodes starting from root that will essentially give the same binary search tree.

Given a bst, say

  3
 /  \\
1             


        

Answer 1

here is another concise recursion based easy to understand solution:

from binarytree import  Node, bst, pprint

def allsequences1(root):
    if not root:
        return None
    lt = allsequences1(root.left)
    rt = allsequences1(root.right)
    ret = []
    if not lt and not rt:
        ret.append([root])
    elif not rt:
        for one in lt:
            ret.append([root]+one)
    elif not lt:
        for two in rt:
            ret.append([root]+two)
    else:
        for one in lt:
            for two in rt:
                ret.append([root]+one+two)
                ret.append([root]+two+one)
    return ret



if __name__=="__main__":
    n = int(input("what is height of tree?"))
    my_bst = bst(n)
    pprint(my_bst)
    seg = allsequences1(my_bst)
    print("All sequences ..1")
    for i in range(len(seq)):
        print("set %d = " %(i+1), end="")
        print(seq[i])