yandex test

Author: GishB

InterviewAlgorithms/SymetricTree.py

@@ -0,0 +1,51 @@
+# TO DO: Given the root of a binary tree,
+#    check whether it is a mirror of itself
+#    (i.e., symmetric around its center).
+#
+# Definition for a binary tree node.
+from typing import Optional
+
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+#
+# Example №1
+# Input: root = [1,2,2,3,4,4,3]
+# Output: true
+#
+# Example №2
+# Input: root = [1,2,2,null,3,null,3]
+# Output: false
+#
+def tree_go(root_r: Optional[TreeNode], root_l: Optional[TreeNode]):
+    if root_r is None and root_l is None:
+        return True
+    elif root_r is None or root_l is None:
+        return False
+    return (root_r.val == root_l.val
+            and
+            tree_go(root_r=root_r.left, root_l=root_l.right)
+            and
+            tree_go(root_r=root_r.right, root_l=root_l.left)
+            )
+
+def check_tree(root: Optional[TreeNode]) -> bool:
+    if not root:
+        return True
+    else:
+        return tree_go(root_l=root.left, root_r=root.right)
+
+
+if __name__ == "__main__":
+    example_root = TreeNode(val=1,
+                            left=TreeNode(val=2,
+                                          left=None,
+                                          right=TreeNode(val=3, left=None, right=None)),
+                            right=TreeNode(val=2,
+                                           left=TreeNode(val=3, left=None, right=None),
+                                           right=TreeNode(val=3, left=None, right=None))
+                            )
+    print(check_tree(example_root))