树的深度优先遍历与广度优先遍历

	//数组每个元素描述的父子节点，节点中node值代表当前节点值，children为子节点node值，node值不重复，请实现对下面key值的层次遍历输出
	let tree = [{
			node: 2,
			children: [3, 9, 4]
		},
		{
			node: 7,
			children: [2]
		},
		{
			node: 3,
			children: [6]
		},
		{
			node: 4,
			children: [5]
		},
		{
			node: 5,
			children: [8]
		},
		{
			node: 10,
			children: [11]
		},
	]
	const visited = new Set();
	let sum = ''
	let arr = []

	function bfs(index) {
		tree.map((item, idex) => {
			if (item.node == index) {
				visited.add(item.node)
				arr.push(item.node)
				sum = idex
			}
		})
		if (tree[sum]) {
			tree[sum].children.forEach((c) => {
				if (!visited.has(c)) {
					visited.add(c);
					arr.push(c)
					bfs(c)
				}
			});
		}
	};

	var ret = function(arr) {
		var res = [arr[0]];
		for (var j = 1; j < arr.length; j++) {
			var repeat = false;
			for (var i = 0; i < res.length; i++) {
				if (arr[j] == res[i]) {
					repeat = true;
					break;
				}
			}
			if (!repeat) {
				res.push(arr[j]);
			}
		}
		return res;
	}
	console.log(bfs(10))
	console.log(bfs(7), visited)
	console.log(ret(arr))