时间复杂度O(n)的数组转树结构算法
最近的工作单中遇到了这个问题，将接口给的数据结构转成树结构，于是就写了这个算法
测试数据
var flatArr = [
{ id: 4, title: "节点4", parent_id: 3 },
{ id: 5, title: "节点5", parent_id: 4 },
{ id: 6, title: "节点6", parent_id: 2 },
{ id: 1, title: "节点1", parent_id: 0 },
{ id: 2, title: "节点2", parent_id: 0 },
{ id: 3, title: "节点3", parent_id: 2 },
];
完整代码
function Node(id, title) {
this.id = id;
this.title = title;
this.leaf = true;
this.children = [];
}
Node.prototype.addChild = function (node) {
this.leaf = false;
this.children.push(node);
};
Node.prototype.setTitle = function (title) {
this.title = title;
};
var list = new Map();
flatArr.map(item => {
var node = list.get(item.id);
var parentNode = list.get(item.parent_id);
if (node) {
node.setTitle(item.title);
} else {
node = new Node(item.id, item.title);
list.set(item.id, node);
}
if (parentNode) {
parentNode.addChild(node);
} else {
let p = new Node(item.parent_id, "temp_node");
list.set(item.parent_id, p);
p.addChild(node);
}
});
输出结果
console.log(JSON.stringify(list.get(0).children));
//[{"id":1,"title":"节点1","leaf":true,"children":[]},{"id":2,"title":"节点2","leaf":false,"children":[{"id":6,"title":"节点6","leaf":true,"children":[]},{"id":3,"title":"节点3","leaf":false,"children":[{"id":4,"title":"节点4","leaf":false,"children":[{"id":5,"title":"节点5","leaf":true,"children":[]}]}]}]}]
总结
完美输出
