429. N 叉树的层序遍历（算法200题-70题）

var levelOrder = function(root) {
    const list = []
    const bfs = (node, count = 0) => {
        if(!node) return
        if(list[count]) {
            list[count].push(node.val)
        } else {
            list[count] = [node.val]
        }
        if(node.children) {
            for(let childrenNode of node.children) {
                bfs(childrenNode, count + 1)
            }
        }
    }
    bfs(root)
    return list
};