Class ZigzagOrderVisitor

src/tree/binary/traverse.rs:91–91

Zigzag Level Order Traversal Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level). For example: Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its zigzag level order traversal as: [ [3], [20, 9], [15, 7] ]

///     [15, 7]
/// ]
pub struct ZigzagOrderVisitor;

/// Two elements of a binary search tree (BST) are swapped by mistake.
/// Recover the tree without changing its structure.