js数据处理-复杂树构建

规则

规则
subject_no以小数点为段，每一段数字进行匹配，如：x包含x.y,x.z
未能精确匹配的, x包含x.y.z,x.n.m
未能精确匹配的, x.y包含x.y.z,x.a.b.c.d

初始数据

var no_list = [
        {
            subject_no: '10.3',
        },
        {
            subject_no: '10',
        },
        {
            subject_no: '10.3.1',
        },
        {
            subject_no: '10.4.3.1',
        },
        {
            subject_no: '10.3.2',
        },
        {
            subject_no: '10.4.3',
        },
        {
            subject_no: '10.3.2.1.1',
        },
        {
            subject_no: '10.4.3.2.1',
        },
        {
            subject_no: '10.4.3.2.1.2',
        },
        {
            subject_no: '10.4.3.2.1.0',
        },
        {
            subject_no: '10.4.3.2.1.0.5.6',
        }
    ]

需要处理成的结果数据

var result_tree = [
    {
        subject_no: '10',
        children: [
            {
                subject_no: '10.3',
                children: [
                    {
                        subject_no: '10.3.1',
                    },
                    {
                        subject_no: '10.3.2',
                        children: [
                            {
                                subject_no: '10.3.2.1.1',
                            },
                        ]
                    },
                ]
            },
            {
                subject_no: '10.4.3',
                children: [
                    {
                        subject_no: '10.4.3.1',
                        children: [
                            {
                                subject_no: '10.4.3.2.1',
                                children: [
                                    {
                                        subject_no: '10.4.3.2.1.0',
                                        children: [
                                            {
                                                subject_no: '10.4.3.2.1.0.5.6',
                                            }
                                        ]
                                    },
                                    {
                                        subject_no: '10.4.3.2.1.2',
                                    },
                                ]
                            },
                        ]
                    },
                ]
            },
        ]
    },
]

算法实现

function list2tree(list) {
    // 初始化匹配map
    let map = list.reduce((m, i) => {
        m[i.subject_no] = i
        return m
    }, {})
    let tree = []
    for (let i = 0; i < list.length; i++) {
        let pathArr = list[i].subject_no.split('.')
        //-1的目的是为了避免后面匹配到自己，否则会陷入死循环
        let j = pathArr.length - 1;
        // 遍历路径数组
        for (; j > 0; j--) {
            // 从后往前取，直到map中有数据
            let path = pathArr.slice(0, j).join('.')
            // 有数据就放入children
            if (map[path]) {
                if (!map[path].children) {
                    map[path].children = []
                }
                map[path].children.push(list[i])
                break
            }
        }
        j === 0 && tree.push(list[i])
    }
    return tree
}
console.log(list2tree(no_list))

https://web03.cn/blog/249