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javascript - 将最大值传播到嵌套树javascript中的父节点

问题描述

有一个嵌套数组，如下所示：

[
    {
        "id": 100,
        "idParent": null,
        "anidatedView": null,
        "state": null,
        "warningHighThreshold": null,
        "dangerHighThreshold": null,
        "lvl": 1,
        "children": [
            {
                "id": 139,
                "idParent": 100,
                "anidatedView": null,
                "state": null,
                "warningHighThreshold": null,
                "dangerHighThreshold": null,
                "lvl": 2,
                "children": [
                    {
                        "id": 186,
                        "idParent": 139,
                        "anidatedView": 279,
                        "state": 15.58,
                        "warningHighThreshold": 80,
                        "dangerHighThreshold": 100,
                        "lvl": 3,
                        "children": []
                    },
                    {
                        "id": 189,
                        "idParent": 139,
                        "anidatedView": 193,
                        "state": 40.65,
                        "warningHighThreshold": 80,
                        "dangerHighThreshold": 100,
                        "lvl": 3,
                        "children": []
                    }
                ]
            },
            {
                "id": 140,
                "idParent": 100,
                "anidatedView": null,
                "state": null,
                "warningHighThreshold": null,
                "dangerHighThreshold": null,
                "lvl": 2,
                "children": [
                    {
                        "id": 193,
                        "idParent": 140,
                        "anidatedView": 183,
                        "state": 65.41,
                        "warningHighThreshold": 92,
                        "dangerHighThreshold": 100,
                        "lvl": 3,
                        "children": []
                    }
                ]
            },
            {
                "id": 141,
                "idParent": 100,
                "anidatedView": null,
                "state": null,
                "warningHighThreshold": null,
                "dangerHighThreshold": null,
                "lvl": 2,
                "children": [
                    {
                        "id": 194,
                        "idParent": 141,
                        "anidatedView": 143,
                        "state": 60.77,
                        "warningHighThreshold": 90,
                        "dangerHighThreshold": 100,
                        "lvl": 3,
                        "children": []
                    },
                    {
                        "id": 195,
                        "idParent": 141,
                        "anidatedView": 436,
                        "state": 59.13,
                        "warningHighThreshold": 90,
                        "dangerHighThreshold": 100,
                        "lvl": 3,
                        "children": []
                    }
                ]
            }
        ]
    }
]

我正在尝试将状态的最大值（也是该最大节点的警告高阈值和危险高阈值）传播到所有父节点。
状态和阈值将始终在树的最后一级可用。

知道如何通过递归来做到这一点吗？

提前致谢！

标签： javascriptrecursionnested-lists

解决方案

我终于设法解决了这个问题。我把我的解决方案留给那些可能有同样问题的人。

const populateState = item => {
  if (item.children.length) {
    const maxValue = item.children
      .map(child => populateState(child))
      .filter(({ state }) => state != null)
      .reduce((maxValue, value) => (value.state > maxValue.state ? value : maxValue), { state: -1 })
    item.state = maxValue.state
    item.warningHighThreshold = maxValue.warningHighThreshold
    item.dangerHighThreshold = maxValue.dangerHighThreshold
    return maxValue
  } else {
    const { state, warningHighThreshold, dangerHighThreshold } = item
    return { state, warningHighThreshold, dangerHighThreshold }
  }
}

用法：（
数组变量是我在问题中定义的列表）

populateState({ children: array})

欢迎任何代码增强。

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