naive solution for "117. Populating Next Right Pointers in Each Node II"

src/populating_next_right_pointers_in_each_node_ii.py

@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+from collections import deque
+
+
+class Node:
+    def __init__(
+        self,
+        val: int = 0,
+        left: Node | None = None,
+        right: Node | None = None,
+        next: Node | None = None,
+    ):
+        self.val = val
+        self.left = left
+        self.right = right
+        self.next = next
+
+
+class Solution:
+    def connect(self, root: Node | None) -> Node | None:
+        if not root:
+            return None
+
+        queue: deque[Node] = deque()
+        queue.append(root)
+
+        while queue:
+            for i in range(len(queue) - 1):
+                queue[i].next = queue[i + 1]
+            for _ in range(len(queue)):
+                node = queue.popleft()
+                if node.left:
+                    queue.append(node.left)
+                if node.right:
+                    queue.append(node.right)
+
+        return root

tests/test_populating_next_right_pointers_in_each_node_ii.py

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+from src.populating_next_right_pointers_in_each_node_ii import Node
+from src.populating_next_right_pointers_in_each_node_ii import Solution
+
+
+def test_example():
+    n7 = Node(7)
+    n3 = Node(3, right=n7)
+    n4 = Node(4)
+    n5 = Node(5)
+    n2 = Node(2, left=n4, right=n5)
+    n1 = Node(1, left=n2, right=n3)
+
+    Solution().connect(n1)
+
+    assert n1.next is None
+    assert n2.next is n3 and n3.next is None
+    assert n4.next is n5 and n5.next is n7 and n7.next is None
+
+
+def test_empty():
+    assert Solution().connect(None) is None