diff --git a/cracking_the_code/chapter4/list_of_depths.py b/cracking_the_code/chapter4/list_of_depths.py
new file mode 100644
index 0000000..258d91e
--- /dev/null
+++ b/cracking_the_code/chapter4/list_of_depths.py
@@ -0,0 +1,36 @@
+import collections
+
+
+def dfs_tree2list(node, lvl, arr):
+    if node is None:
+        return
+    if lvl >= len(arr):
+        linked_lst = collections.deque()  # linkedlist
+        arr.append(linked_lst)
+    arr[lvl].append(node.value)
+    dfs_tree2list(node.left, lvl+1, arr)
+    dfs_tree2list(node.right, lvl+1, arr)
+
+
+def dft_tree2list(node, arr):
+    current = collections.deque()  # linkedlist
+    current.append(node)
+
+    while current:  # while not empty
+        arr.append(current)
+        parents = current
+        for parent in parents:
+            if parent.left:
+                current.append(parent.left)
+            if parent.right:
+                current.append(parent.right)
+
+
+def main():
+    # TODO: Create Tree
+    dfs_tree2list([], 0, [])
+
+
+if __name__ == "__main__":
+    main()
+