26. leetcode 350. Intersection of Two Arrays II

350. Intersection of Two Arrays II

Given two arrays, write a function to compute their intersection.

Example:

Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2,
2].

Note:

• Each
  element in the result should appear as many times as it shows in both
  arrays.
• The
  result can be in any order.

Follow
up:

• What
  if the given array is already sorted? How would you optimize your
  algorithm?
• What
  if nums1's size is
  small compared to nums2's
  size? Which algorithm is better?
• What
  if elements of nums2 are stored on disk, and the
  memory is limited such that you cannot load all elements into the memory
  at once?

思路：输出两个整形数组共同存在的元素。利用C++的map