EDIT: Here's a rephrase of the question for clarity (apologies for confusion):

QUESTION : Given an array limits and an array punct_arr where both are sorted, return an output array of values separation_index where separation_index[i] is the closest value in punct_arr to limits[i]. It follows that separation_index will be of the same size as limits.

So, say I have two arrays:

limits = [280, 560]

punct_arr = [5, 99, 151, 159, 255, 352, 462, 502, 519, 531, 556, 602]

Expected Outcome: [255, 556]

The outcome should always be the same length as the limits array.

Here's what I got so far:

    for (var limit = 0; limit < limits.length; limit  ) {
        for (var punct = 0; punct < punct_arr.length; punct  ) {
            if (Math.abs(punct_arr[punct - 1] - limits[limit]) < (Math.abs(punct_arr[punct] - limits[limit])) && (Math.abs(punct_arr[punct] - limits[limit]) < (Math.abs(punct_arr[punct] - limits[limit   1])))) {
                separation_index.push(punct_arr[punct-1]);
            }
        }
    }

Thanks in advance!

CodePudding user response：

Here's one way. I just adjusted a bit your code.

const limits = [280, 560]

const punct_arr = [5, 99, 151, 159, 255, 352, 462, 502, 519, 531, 556, 602]

function closestLimits(limits, arr) {
  const diff = []
  const separation_index = []
  let closest
  for (var limit = 0; limit < limits.length; limit  ) {
    diff.length = 0
    for (var punct = 0; punct < arr.length; punct  ) {
      var m = Math.abs(arr[punct] - limits[limit]);
      diff.push(m)
      if (m <= Math.min(...diff)) {
        smallest = arr[punct]
      }
    }
    separation_index.push(smallest);
  }
  return separation_index
}
console.log(closestLimits(limits, punct_arr))

CodePudding user response：

Here's a decomposed approach where we start writing at a high-level and define auxiliary helper functions along the way -

function closest (limits, inputs) {
  return limits.map(v => closest1(v, inputs))
}

function closest1 (one, many) {
  return many.reduce((r, v) =>
    delta(r, one) < delta(v, one) ? r : v,
    -Infinity
  )
}

function delta (a, b) {
  return Math.abs(a - b)
}

const limits = [280, 560]

const inputs = [5, 99, 151, 159, 255, 352, 462, 502, 519, 531, 556, 602]

console.log(closest(limits, inputs))

[ 255, 556 ]