使用JavaScript构建层次树

Question

使用JavaScript构建层次树

3

我正在尝试从我从 SOLR 得到的属性中构建类别、子类别等层次树形结构。输入的格式如下：

['445',
79,
'398',
73,
'710',
32,
'398|760',
28,
'398|760|779',
28,
'445|446',
10]

单引号中的数据表示类别，之后的数字表示频率。

给定上述数组，则需要输出以下格式：

[
    {
        "id": 445,
        "count": 79,
        "children": [
            {
                "id": 446,
                "count": 10
            }
        ]
    },
    {
        "id": 398,
        "count": 73,
        "children": [
            {
                "id": 760,
                "count": 28,
                "children": [
                    {
                        "id": 779,
                        "count": 28
                    }
                ]
            }
        ]
    },
    {
        "id": 710,
        "count": 32
    }
]

我想要用同样的元素构建一棵树，但是一直没有成功。有没有人知道如何让它工作，或者有没有其他时间效率更高的解决方案。

谢谢！

- Ajay Pal Singh

我对这里预期的trie用途感到相当困惑。通常，你会在JavaScript中创建一个trie用于自动完成，比如当用户输入一个类别名称时，而显然你正在处理类别ID...你希望实现什么样的trie结构呢？给定398|730|607，我可以为您设计一个树，例如{398:{freq:73,760:{freq:28,779:{freq:28}},730:{freq:18,607:{freq:18}}}}，这是您想要的吗？还是您希望基于类别名称构建一棵树，像这样：{'j':{'a':{'v':{'a':{...}}}}}？ - Ultimater

我已经编辑了问题，以展示我正在努力实现的最终输出结果，我考虑使用Trie作为字典，然后使用Trie来构建最终的数据结构（而Radix树不仅仅用于自动完成）。但是只要复杂度保持在O（n）的范围内，任何其他方法都可以使用。 - Ajay Pal Singh

为什么不先将数据分割，以便首先获取树的顶点，然后再获取边缘？或者它总是这样的：你首先获取边缘，然后获取顶点？ - Christo S. Christov

源数据的来源超出了我的控制，因此我不能假设它，但我可以修改它以符合您提到的格式 - 但我无法理解这将如何有助于减少复杂性。我通过在桶内递归地形成桶来解决了问题 - 但是很容易预料到，时间和空间方面都会产生可怕的权衡！ - Ajay Pal Singh

1个回答

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Ultimater · Accepted Answer

这应该可以满足您的需求，但是请注意，没有子节点的节点仍将具有node.children属性，因此您可以使用node.children.length查看树中任何节点的子节点数量。

var o=["445", 79, "398", 73, "710", 32, "398|760", 28, "398|760|779", 28, "445|446", 26, "710|1045", 25, "445|452", 24, "381", 19, "445|943", 19, "398|730", 18, "398|730|607", 18, "367", 16, "445|446|451", 15, "351", 14, "351|363", 14, "351|363|365", 14, "381|395", 14, "381|395|566", 14, "445|526", 14, "445|526|769", 14, "367|372", 12, "710|1045|1119", 11, "398|410", 10, "398|483", 9, "445|452|743", 8, "367|372|377", 7, "398|483|757", 7, "445|446|792", 7, "445|452|744", 7, "445|452|719", 6, "398|410|411", 5];

var nodeMap={};
var nodeLevels=[];
for(var i=0;i<o.length;i+=2)
{
    var catLineage=o[i].split('|');
    var cat=catLineage[catLineage.length-1];
    var depth=catLineage.length;
    while(depth>nodeLevels.length){nodeLevels.push([]);}
    nodeMap[cat]={id:cat,count:o[i+1],depth:depth,parents:catLineage.slice(0,catLineage.length-1)};
    nodeLevels[depth-1].push(cat);
}
var tree=[];
var treeNodeLookup={};
for(var i=0;i<nodeLevels.length;i++)
{
    for(var j=0;j<nodeLevels[i].length;j++)
    {
        var nodeId=nodeLevels[i][j];
        var nodeDepth=nodeMap[nodeId].depth;
        var nodeCount=nodeMap[nodeId].count;
        var parents=nodeMap[nodeId].parents;
        var pointer={children:tree};
        if(parents.length>0){pointer=treeNodeLookup[parents[0]];}
        var node={id:nodeId,count:nodeCount,children:[]};
        pointer.children.push(node);
        treeNodeLookup[nodeId]=pointer.children[pointer.children.length-1];
    }
}
console.log(tree);

使用 console.log(JSON.stringify(tree));，我的输出如下：

[{"id":"445","count":79,"children":[{"id":"446","count":26,"children":[]},{"id":"452","count":24,"children":[]},{"id":"943","count":19,"children":[]},{"id":"526","count":14,"children":[]},{"id":"451","count":15,"children":[]},{"id":"769","count":14,"children":[]},{"id":"743","count":8,"children":[]},{"id":"792","count":7,"children":[]},{"id":"744","count":7,"children":[]},{"id":"719","count":6,"children":[]}]},{"id":"398","count":73,"children":[{"id":"760","count":28,"children":[]},{"id":"730","count":18,"children":[]},{"id":"410","count":10,"children":[]},{"id":"483","count":9,"children":[]},{"id":"779","count":28,"children":[]},{"id":"607","count":18,"children":[]},{"id":"757","count":7,"children":[]},{"id":"411","count":5,"children":[]}]},{"id":"710","count":32,"children":[{"id":"1045","count":25,"children":[]},{"id":"1119","count":11,"children":[]}]},{"id":"381","count":19,"children":[{"id":"395","count":14,"children":[]},{"id":"566","count":14,"children":[]}]},{"id":"367","count":16,"children":[{"id":"372","count":12,"children":[]},{"id":"377","count":7,"children":[]}]},{"id":"351","count":14,"children":[{"id":"363","count":14,"children":[]},{"id":"365","count":14,"children":[]}]}]