leetcode

commit 8459f619fde2d607bdefdde05d9c61c7ca072391
parent f6adfd3d0d32487e8e45eaba341b80704227b3a9
Author: Jack Sangdahl <jack@pngu.org>
Date:   Mon,  9 Feb 2026 15:52:08 -0700

chore: Add Python ListNode, TreeNode helpers

Diffstat:
M
leetcode.py
 | 
27
+++++++++++++++++++++++++++
M
readme.md
 | 
34
+++++++++++++++++++++++++++++++---

2 files changed, 58 insertions(+), 3 deletions(-)
diff --git a/leetcode.py b/leetcode.py
@@ -26,6 +26,23 @@ def treenode_build(vals):
     return root
 
 
+def treenode_print(root):
+    if not root:
+        return
+    q, res = deque([root]), []
+    while q:
+        curr = q.popleft()
+        if curr:
+            res.append(str(curr.val))
+            q.append(curr.left)
+            q.append(curr.right)
+        else:
+            res.append("null")
+    while res and res[-1] == "null":
+        res.pop()
+    print(res)
+
+
 class ListNode:
     def __init__(self, val=0, next=None):
         self.val = val
@@ -41,3 +58,13 @@ def listnode_build(vals):
         curr.next = ListNode(i)
         curr = curr.next
     return head
+
+
+def listnode_print(head):
+    if not head:
+        return
+    res, curr = [], head
+    while curr:
+        res.append(str(curr.val))
+        curr = curr.next
+    print(res)
diff --git a/readme.md b/readme.md
@@ -1,10 +1,11 @@
-## Leetcode
+# Leetcode
 
 This repository contains my Leetcode solutions for [user 0x6A73](https://leetcode.com/u/0x6A73). Generally, the daily challenge is solved in both C and Python3.
 
-### Notes
+## Notes
 
-The [`leetcode.h`](leetcode.h) header file contains various includes, standard Leetcode structs (`ListNode`, `TreeNode`), and some helpful macros, like calculating the size of a C array using `builtin` functions.
+### C Utilities
+The [`leetcode.h`](leetcode.h) header file contains various includes, standard Leetcode structs (`ListNode`, `TreeNode`), and some helpful macros, like calculating the size of a array using `builtin` functions.
 ```c
 #define IS_ARRAY(value)                                                        \
   (!__builtin_types_compatible_p(typeof((value)), typeof(&(value)[0])))
@@ -29,6 +30,7 @@ int main() {
     int input[] = {0, 3, 1, 0, 4, 5, 2, 0};
     struct ListNode *head = listnode_build(input, ARRAY_SIZE(input));
     listnode_print(head);
+    listnode_free(head);
 }
 ```
 
@@ -43,6 +45,7 @@ int main() {
     // this value, use treenode_create() to individually create each node
     struct TreeNode *root = treenode_build(input, ARRAY_SIZE(input));
     treenode_print(root);
+    treenode_free(root);
 }
 ```
 
@@ -59,3 +62,28 @@ int main() {
   two_d_arr_free(edges);
 }
 ```
+
+### Python Utilities
+
+Similar to the above, [`leetcode.py`](leetcode.py) contains helpers to work with Leetcode data structures.
+
+#### `ListNode` data type
+
+```python
+from leetcode import ListNode, listnode_build, listnode_print
+
+if __name__ == "__main__":
+    head = listnode_build(vals=[0, 3, 1, 0, 4, 5, 2, 0])
+    listnode_print(head)
+```
+
+#### `TreeNode` data type
+
+```python
+from leetcode import TreeNode, treenode_build, treenode_print
+
+if __name__ == "__main__":
+    root = treenode_build(vals=[3, 9, 20, None, None, 15, 7])
+    # note: None denotes a 'null' leaf
+    treenode_print(root)
+```