Add example

Author: JerAguilon

interactiveExamples/counting_trees.py

@@ -0,0 +1,6 @@
+# Given an int n, return the number of possible trees with n nodes you can construct
+# Example: n = 1 --> 1, the single node
+#          n = 2 --> 2, a parent node with a left child and a parent node with a right child
+
+def solution(n):
+    pass

interactiveExamples/tree_to_linked_list.py

@@ -8,5 +8,35 @@ def __init__(self, val, left=None, right=None):
         self.left = left
         self.right = right
 
+    def __str__(self):
+        return self.val
+
 def solution(root):
-    pass
+    if root is None:
+        return root
+    if root.left is None and root.right is None:
+        return root
+
+    stack = []
+    stack.append(root)
+
+    head = root
+    tail = None
+
+    while len(stack) > 0:
+        curr = stack.pop()
+
+        if curr.left is not None:
+            stack.append(curr.left)
+        if curr.right is not None:
+            stack.append(curr.right)
+
+        if tail is None:
+            tail = curr
+            tail.left = None
+        else:
+            tail.right = curr
+            curr.left = tail
+            tail = curr
+            tail.right = None
+    return head