LeetCode: Intersection Of Two Arrays II Solution

1var intersect = function (nums1, nums2) {
2  const getElOccMap = arr =>
3    arr.reduce((acc, el) => acc.set(el, (acc.get(el) || 0) + 1), new Map())
4  const map1 = getElOccMap(nums1)
5  const map2 = getElOccMap(nums2)
6  const res = []
7  for (const [el, occ] of map1) {
8    if (map2.has(el)) {
9      res.push(Array(Math.min(occ, map2.get(el))).fill(el))
10    }
11  }
12  return res.flat()
13}