在Javascript中实现数组备份BST

class Node {
  constructor(value) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

let bst = [];

function insert(value) {
  const newNode = new Node(value);

  if (bst.length === 0) {
    bst.push(newNode);
  } else {
    let current = bst[0];
    while (true) {
      if (value < current.value) {
        if (current.left === null) {
          current.left = newNode;
          break;
        }
        current = current.left;
      } else {
        if (current.right === null) {
          current.right = newNode;
          break;
        }
        current = current.right;
      }
    }
  }
}

function backup() {
  const backupArray = [];

  function traverse(node) {
    if (node !== null) {
      backupArray.push(node.value);
      traverse(node.left);
      traverse(node.right);
    }
  }

  traverse(bst[0]);

  return backupArray;
}

insert(5);
insert(3);
insert(7);
insert(2);
insert(4);
insert(6);
insert(8);

const backupArray = backup();
console.log(backupArray); // 输出：[5, 3, 2, 4, 7, 6, 8]