subtree(users/wpcarro): docking briefcase at '24f5a642' r/3226

git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c09813172c79820bcf526bb10cf4208
git-subtree-split: 24f5a642af3aa1627bbff977f0a101907a02c69f
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789

1 files changed, 26 insertions, 0 deletions

diff --git a/users/wpcarro/scratch/facebook/kth-to-last-node-in-singly-linked-list.py b/users/wpcarro/scratch/facebook/kth-to-last-node-in-singly-linked-list.py
new file mode 100644
index 0000000000..dd258d924d
--- /dev/null
+++ b/users/wpcarro/scratch/facebook/kth-to-last-node-in-singly-linked-list.py
@@ -0,0 +1,26 @@
+from linked_list import Node, from_list
+
+def kth_to_last_node(k, node):
+    one = node
+    two = node
+    for _ in range(k - 1):
+        if not one:
+            return None
+        one = one.next
+    while one.next:
+        one = one.next
+        two = two.next
+    return two.value
+
+
+xs = from_list(["Angel Food", "Bundt", "Cheese", "Devil's Food", "Eccles"])
+result = kth_to_last_node(2, xs)
+print(result)
+assert result == "Devil's Food"
+print("Success!")
+
+xs = from_list(["Angel Food", "Bundt"])
+result = kth_to_last_node(30, xs)
+print(result)
+assert result is None
+print("Success!")