Javascript 查找特定累积距离的数组数组中出现的总数

var input = {
  1: [
    [1, 5, 6],
    [2, 41],
    [4, 7, 11]
  ],
  2: [
    [1, 5, 6],
    [2, 41],
    [3, 7, 11]
  ]
}

function cartesianProduct(arr) {
  return arr.reduce(function(a, b) {
    return a.map(function(x) {
      return b.map(function(y) {
        return x.concat([y]);
      })
    }).reduce(function(a, b) {
      return a.concat(b)
    }, [])
  }, [
    []
  ])
}

function distance(arr) {
  arr.sort(function(a,b) {
    return +a - +b;
  });
  var total = 0;
  for (var i = 1; i < arr.length; i++) {
    total += (arr[i] - arr[i - 1] - 1)
  }
  return total;
}

function count_index(arrs, proximity) {
  var product = cartesianProduct(arrs);
  var count = 0;
  product.forEach(function(series) {
    if (distance(series) <= proximity) {
      console.log("found: " + series)
      count++
    }
  })
  return count
}

var result = {}
var proximity = 2;
Object.entries(input).forEach(function([key, value]) {
  result[key] = count_index(value, proximity)
})
console.log(result)