BinaryTreeLevelorder

BinaryTreeLevelorder.js

levelOrder() {
  if (!this.root) return [];
  var array = [];
  search(this.root, 1, 1);

  function search(node, level, index) {
    if (node) {
      const count = Math.pow(2, level - 1);
      if (array.length < level) {
        array.push(Array(count).fill(""));
      }
      var arr = array[level - 1];
      arr[index - 1] = node;
      const leftIndex = 2 * index - 1;
      const rightIndex = 2 * index;
      search(node.left, level + 1, leftIndex);
      search(node.right, level + 1, rightIndex);
    } else {
      return;
    }
  }

  return array;
}