diff options
Diffstat (limited to 'linked_list_binary_tree.py')
-rw-r--r-- | linked_list_binary_tree.py | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/linked_list_binary_tree.py b/linked_list_binary_tree.py new file mode 100644 index 0000000..b9e8bd0 --- /dev/null +++ b/linked_list_binary_tree.py @@ -0,0 +1,104 @@ +# 1367. Linked List in Binary Tree + +""" +given a binary tree 'root' and a linked list with 'head' as the first node. +return true if all the elements in the linked list starting from the 'head' +correspond to some downward path connected in the binary tree otherwise +return false. in this context downward path means a path that starts at some +node and goes downwards. +""" + + +# Definition for singly-linked list. +class ListNode(object): + def __init__(self, val=0, next=None): + self.val = val + self.next = next + + +# Definition for a binary tree node. +class TreeNode(object): + def __init__(self, val=0, left=None, right=None): + self.val = val + self.left = left + self.right = right + + +class Solution(object): + def isSubPath(self, head, root): + """ + :type head: ListNode + :type root: TreeNode + :rtype: bool + """ + + def dfs(head, root): + if not head: + return True + if not root: + return False + return root.val == head.val and ( + dfs(head.next, root.left) or dfs(head.next, root.right) + ) + + if not head: + return True + if not root: + return False + return ( + dfs(head, root) + or self.isSubPath(head, root.left) + or self.isSubPath(head, root.right) + ) + + +if __name__ == "__main__": + obj = Solution() + print( + obj.isSubPath( + head=[4, 2, 8], + root=[ + 1, + 4, + 4, + None, + 2, + 2, + None, + 1, + None, + 6, + 8, + None, + None, + None, + None, + 1, + 3, + ], + ) + ) + print( + obj.isSubPath( + head=[1, 4, 2, 6], + root=[ + 1, + 4, + 4, + None, + 2, + 2, + None, + 1, + None, + 6, + 8, + None, + None, + None, + None, + 1, + 3, + ], + ) + ) |