递归遍历

深度优先遍历 - 递归写法

function deepTraversal(node) {
  let nodes = [];

  if (node != null) {
    nodes.push[node];
    let childrens = node.children;
    for (let i = 0; i < childrens.length; i++) deepTraversal(childrens[i]);
  }

  return nodes;
}

深度优先遍历 - 迭代写法

function deepTraversal(node) {
  let nodes = [];
  if (node != null) {
    let stack = [];
    //同来存放将来要访问的节点
    stack.push(node);

    while (stack.length != 0) {
      let item = stack.pop();
      //正在访问的节点
      nodes.push(item);
      let childrens = item.children;
      for (let i = childrens.length - 1; i >= 0; i--)
        //将现在访问点的节点的子节点存入 stack，供将来访问 )
        stack.push(childrens[i]);
    }
  }

  return nodes;
}

广度优先遍历 - 递归写法

function wideTraversal(node) {
  let nodes = [],
    i = 0;
  if (node != null) {
    nodes.push(node);
    wideTraversal(node.nextElementSibling);
    node = nodes[i++];
    wideTraversal(node.firstElementChild);
  }
  return nodes;
}

广度优先遍历 - 迭代写法

function wideTraversal(node) {
  let nodes = [],
    i = 0;
  while (node != null) {
    nodes.push(node);
    node = nodes[i++];
    let childrens = node.children;
    for (let i = 0; i < childrens.length; i++) {
      nodes.push(childrens[i]);
    }
  }
  return nodes;
}