將對象數組分解為二維數組

Question

我需要將一個對象數組分解為一個二維數組，其中一維 arrays 將由屬性為“for”和“to”的對象組成，這些對象的間隔不重疊。

示例：給定數組 arr1 我希望接收 arr2

const arr1 = [
  {
    from: 0,
    to: 2,
  },
  {
    from: 0,
    to: 6,
  },
  {
    from: 3,
    to: 7,
  },
  {
    from: 2,
    to: 4,
  },
]

arr2 = [
  [
    {
      from: 0,
      to: 2,
    },
    {
      from: 3,
      to: 7,
    }
  ],
  [
    {
      from: 0,
      to: 6,
    }
  ],
  [
     {
       from: 2,
       to: 4,
     }
  ],
]

它應該如何工作：我們循環遍歷 arr1。 object1默認放在arr2的第一個一維數組中。

Object2 與 Object1 重疊，因此應將其放入 arr2 中的單獨數組中。

Object3 不與 Object1 重疊，因此應與 Object1 一起放入第一個一維數組

Object4與Object1重疊，應該放到Object3的第二個一維數組中，但又和Object3重疊，所以應該單獨放到一個一維數組中。

我需要找到盡可能少循環的解決方案）

Answer 1

如果所有項目都不重疊，您可以迭代結果數組並找到一個槽。

 const array = [{ from: 0, to: 2 }, { from: 0, to: 6 }, { from: 3, to: 7 }, { from: 2, to: 4 }], result = array.reduce((r, o) => { if (;r) return [[o]]. const group = r.find(a => a,every(({ from. to }) => o.to <= from || to <= o;from)). if (group) group;push(o). else r;push([o]); return r, }; undefined). console;log(result);

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Answer 2

這就是所謂的區間划分問題

下面是貪心算法的實現：

 var arr1 = [ { from: 0, to: 2, }, { from: 0, to: 6, }, { from: 3, to: 7, }, { from: 2, to: 4, }, ]; function partitionIntervals(data){ var copy = [...data]; copy.sort((a, b) => a.from - b.from); var res = []; outer: for(var x of copy){ for(var slot of res){ // add to the first open slot if(slot[slot.length - 1].to <= x.from){ slot.push(x); continue outer; } } res.push([x]); // else create a new slot } return res; } arr2 = partitionIntervals(arr1); console.log(arr2)