基于原生JavaScript的自定义数据聚合问题求助

初始数据 #

const data = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA', site: 'hash1' },
    { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA', site: 'hash2' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA', site: 'hash3' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA', site: 'hash4' },
    { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA', site: 'hash5' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA', site: 'hash6' },
    { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA', site: 'hash7' },
];

聚合规则 #

• 若某个type的所有日期对应的casualties均大于等于设定阈值，需保留在results数组中；
• 若某个type的所有日期对应的casualties均低于阈值，且是唯一符合该条件的type，也需保留在results数组中；
• 若有两个及以上type的所有日期对应的casualties均低于阈值，则这些type不单独出现在results数组中，而是按日期汇总casualties，以type为other的形式展示；
• otherCasualties数组需包含所有满足“所有日期casualties均低于阈值”的type。

示例 #

阈值为9时 #

results = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA' },
];

此时otherCasualties = []

阈值为13时 #

results = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA'},
    { date: '2023-11-01', type: 'other', casualties: 17, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'other', casualties: 8, state: 'NY', country: 'USA' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA' },
];

此时otherCasualties = ['B', 'D']

尝试的代码 #

function processCasualties(data, casualtiesThreshold) {
  const results = [];
  const otherCasualties = [];

  const groupedData = data.reduce((acc, item) => {
    const key = item.type;
    if (!acc[key]) {
      acc[key] = [];
    }
    acc[key].push(item);
    return acc;
  }, {});

  const types = Object.keys(groupedData);

  types.forEach(type => {
    const typeData = groupedData[type];
    const totalCasualties = typeData.reduce((acc, item) => acc + item.casualties, 0);
    const allDatesBelowThreshold = typeData.every(item => item.casualties < casualtiesThreshold);

    if (totalCasualties >= casualtiesThreshold || (allDatesBelowThreshold && types.length === 1)) {
      results.push(...typeData.map(item => ({
        date: item.date,
        type: item.type,
        casualties: item.casualties,
        state: item.state,
        country: item.country,
      })));
    } else if (allDatesBelowThreshold) {
      otherCasualties.push(type);
    } else {
      results.push(...typeData.map(item => ({
        date: item.date,
        type: 'other',
        casualties: totalCasualties,
        state: item.state,
        country: item.country,
      })));
    }
  });

  return { results, otherCasualties };
}

const casualtiesThreshold = 13;

const { results, otherCasualties } = processCasualties(data, casualtiesThreshold);

console.log(results);
console.log(otherCasualties);

修正后的代码 #

function processCasualties(data, casualtiesThreshold) {
  const results = [];
  const otherCasualties = [];

  // 1. 按type分组数据
  const groupedByType = data.reduce((acc, item) => {
    const key = item.type;
    if (!acc[key]) {
      acc[key] = [];
    }
    acc[key].push(item);
    return acc;
  }, {});

  // 2. 筛选出所有满足"所有日期casualties均低于阈值"的type
  const belowThresholdTypes = Object.keys(groupedByType).filter(type => {
    return groupedByType[type].every(item => item.casualties < casualtiesThreshold);
  });

  // 3. 填充otherCasualties数组
  otherCasualties.push(...belowThresholdTypes);

  // 4. 判断是否需要聚合为other
  const needAggregate = belowThresholdTypes.length >= 2;
  const aggregatedOther = {};

  // 处理各类type数据
  Object.keys(groupedByType).forEach(type => {
    const typeData = groupedByType[type];
    const isBelowThreshold = belowThresholdTypes.includes(type);

    if (!isBelowThreshold) {
      // 非阈值以下的type，直接保留原数据
      results.push(...typeData.map(item => ({
        date: item.date,
        type: item.type,
        casualties: item.casualties,
        state: item.state,
        country: item.country,
      })));
    } else if (!needAggregate) {
      // 单个阈值以下的type，直接保留
      results.push(...typeData.map(item => ({
        date: item.date,
        type: item.type,
        casualties: item.casualties,
        state: item.state,
        country: item.country,
      })));
    } else {
      // 需聚合的type，按日期累加casualties
      typeData.forEach(item => {
        const key = item.date;
        if (!aggregatedOther[key]) {
          aggregatedOther[key] = {
            date: item.date,
            type: 'other',
            casualties: 0,
            state: item.state,
            country: item.country,
          };
        }
        aggregatedOther[key].casualties += item.casualties;
      });
    }
  });

  // 5. 将聚合后的other数据加入结果
  if (needAggregate) {
    results.push(...Object.values(aggregatedOther));
  }

  // 6. 按日期排序结果，与示例顺序一致
  results.sort((a, b) => new Date(a.date) - new Date(b.date));

  return { results, otherCasualties };
}

// 测试用例
const data = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA', site: 'hash1' },
    { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA', site: 'hash2' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA', site: 'hash3' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA', site: 'hash4' },
    { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA', site: 'hash5' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA', site: 'hash6' },
    { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA', site: 'hash7' },
];

// 测试阈值9
console.log("阈值为9时：");
const { results: results9, otherCasualties: other9 } = processCasualties(data, 9);
console.log(results9);
console.log(other9);

// 测试阈值13
console.log("阈值为13时：");
const { results: results13, otherCasualties: other13 } = processCasualties(data, 13);
console.log(results13);
console.log(other13);

修正说明 #

1. 原代码问题：

   • 错误用type的总伤亡数判断是否保留，不符合规则1（规则要求该type的每一条数据伤亡数都≥阈值）；
   • 未正确统计需聚合的阈值以下type数量，聚合逻辑错误（直接使用type总伤亡数而非按日期累加）；
   • 缺少聚合后other数据的日期分组逻辑。

2. 核心修正点：

   • 先筛选出所有满足"全日期伤亡数低于阈值"的type集合；
   • 根据集合长度判断是否需要聚合为other；
   • 对需聚合的type按日期累加伤亡数，统一生成other条目；
   • 最后对结果按日期排序，与示例输出顺序匹配。

内容的提问来源于stack exchange，提问作者user1352042