I need to break an array of objects into a 2-dimensional array where 1-dimensional arrays would consist of objects which have their attributes ‘for’ and ‘to’ being not overlapping intervals.
Example: Given array arr1 I wish to receive 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,
}
],
]
How it should work: We loop through the arr1. Object1 should be put into the first 1-dimensional array in arr2 by default.
Object2 overlaps with Object1 so it should be put into a separate array in arr2.
Object3 does not overlap Object1 so it should be put into the first 1-dimensional array with Object1
Object4 overlaps with Object1 so it should be put into the second 1-dimensional array to Object3, but it also overlaps with Object3 so it should be put into a separate 1-dimensional array.
I need to find the solution with as less loops as possible)
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Answer
You could iterate the result array and find a slot if all items do not overlap.
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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