Add Mirror a Binary Tree solution

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()

data_structures/binary_tree/mirror_binary_tree.py

@@ -0,0 +1,153 @@
+"""
+Given the root of a binary tree, mirror the tree, and return its root.
+
+Leetcode problem reference: https://leetcode.com/problems/mirror-binary-tree/
+"""
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+ """
+ A Node has value variable and pointers to Nodes to its left and right.
+ """
+
+ value: int
+ left: Node | None = None
+ right: Node | None = None
+
+ def __iter__(self) -> Iterator[int]:
+ if self.left:
+ yield from self.left
+ yield self.value
+ if self.right:
+ yield from self.right
+
+ def __len__(self) -> int:
+ return sum(1 for _ in self)
+
+ def mirror(self) -> Node:
+ """
+ Mirror the binary tree rooted at this node by swapping left and right children.
+
+ >>> tree = Node(0)
+ >>> list(tree)
+ [0]
+ >>> list(tree.mirror())
+ [0]
+ >>> tree = Node(1, Node(0), Node(3, Node(2), Node(4, None, Node(5))))
+ >>> tuple(tree)
+ (0, 1, 2, 3, 4, 5)
+ >>> tuple(tree.mirror())
+ (5, 4, 3, 2, 1, 0)
+ """
+ self.left, self.right = self.right, self.left
+ if self.left:
+ self.left.mirror()
+ if self.right:
+ self.right.mirror()
+ return self
+
+
+def make_tree_seven() -> Node:
+ r"""
+ Return a binary tree with 7 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ / \
+ 4 5 6 7
+
+ >>> tree_seven = make_tree_seven()
+ >>> len(tree_seven)
+ 7
+ >>> list(tree_seven)
+ [4, 2, 5, 1, 6, 3, 7]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.left = Node(6)
+ tree.right.right = Node(7)
+ return tree
+
+
+def make_tree_nine() -> Node:
+ r"""
+ Return a binary tree with 9 nodes that looks like this:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ >>> tree_nine = make_tree_nine()
+ >>> len(tree_nine)
+ 9
+ >>> list(tree_nine)
+ [7, 4, 8, 2, 5, 9, 1, 3, 6]
+ """
+ tree = Node(1)
+ tree.left = Node(2)
+ tree.right = Node(3)
+ tree.left.left = Node(4)
+ tree.left.right = Node(5)
+ tree.right.right = Node(6)
+ tree.left.left.left = Node(7)
+ tree.left.left.right = Node(8)
+ tree.left.right.right = Node(9)
+ return tree
+
+
+def main() -> None:
+ r"""
+ Mirror binary trees with the given root and returns the root
+
+ >>> tree = make_tree_nine()
+ >>> tuple(tree)
+ (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ >>> tuple(tree.mirror())
+ (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+ nine_tree:
+ 1
+ / \
+ 2 3
+ / \ \
+ 4 5 6
+ / \ \
+ 7 8 9
+
+ The mirrored tree looks like this:
+ 1
+ / \
+ 3 2
+ / / \
+ 6 5 4
+ / / \
+ 9 8 7
+ """
+ trees = {"zero": Node(0), "seven": make_tree_seven(), "nine": make_tree_nine()}
+ for name, tree in trees.items():
+ print(f" The {name} tree: {tuple(tree)}")
+ # (0,)
+ # (4, 2, 5, 1, 6, 3, 7)
+ # (7, 4, 8, 2, 5, 9, 1, 3, 6)
+ print(f"Mirror of {name} tree: {tuple(tree.mirror())}")
+ # (0,)
+ # (7, 3, 6, 1, 5, 2, 4)
+ # (6, 3, 1, 9, 5, 2, 8, 4, 7)
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ main()