Feb 21

Author: siddydutta

2025-02-February-LeetCoding-Challenge/Find Elements in a Contaminated Binary Tree.py

@@ -0,0 +1,38 @@
+from typing import Optional
+
+
+# Definition for a binary tree node.
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class FindElements:
+    def __init__(self, root: Optional[TreeNode]):
+        self.node_vals = set()
+
+        def dfs(node: Optional[TreeNode], val: int) -> None:
+            if node is None:
+                return
+            node.val = val
+            self.node_vals.add(val)
+            dfs(node.left, 2*val + 1)
+            dfs(node.right, 2*val + 2)
+        dfs(root, 0)
+
+    def find(self, target: int) -> bool:
+        return target in self.node_vals
+
+
+def main():
+    root = TreeNode(-1)
+    root.right = TreeNode(-1)
+    obj = FindElements(root)
+    assert obj.find(1) is False
+    assert obj.find(2) is True
+
+
+if __name__ == '__main__':
+    main()

2025-02-February-LeetCoding-Challenge/README.md

@@ -24,7 +24,7 @@
 | February 18 | [2375. Construct Smallest Number From DI String](https://leetcode.com/problems/construct-smallest-number-from-di-string/) | Medium | Unsolved |
 | February 19 | [1415. The k-th Lexicographical String of All Happy Strings of Length n](https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n/) | Medium | Unsolved |
 | February 20 | [1980. Find Unique Binary String](https://leetcode.com/problems/find-unique-binary-string/) | Medium | Solved |
-| February 21 | []() |  |  |
+| February 21 | [1261. Find Elements in a Contaminated Binary Tree](https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree/) | Medium | Solved |
 | February 22 | []() |  |  |
 | February 23 | []() |  |  |
 | February 24 | []() |  |  |
@@ -38,5 +38,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 6 | 6 | 0 |
-| Medium | 13 | 10 | 3 |
+| Medium | 14 | 11 | 3 |
 | Hard   | 0 | 0 | 0 |