LeetCode349. Intersection of two arrays (using Map)

Topic describes

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

Input: nums1 = [1,2,2,1], nums2 = [2,2] output: [2]

//
// 1, nums1, nums2
// 2, set up a dictionary mapping relationship, record the values in nums1
// 3, run through nums2 to find the same value as nums1

//
// 1, create a new dictionary, iterate through nums1, and populate the dictionary
// 2, iterates through nums2, selects the value in the dictionary, and deletes it from the dictionary
// VX:mike_fss888(add friends wow 😝)

/ * * *@param {number[]} nums1
 * @param {number[]} nums2
 * @return {number[]}* /
 
var intersection = function (nums1, nums2) {
  const map = new Map()
  nums1.forEach(n= > {
    map.set(n, true)})const res = []
  nums2.forEach(n= > {
    if (map.get(n)) {
      res.push(n)
      map.delete(n)
    }
  })
  return res
};

// Time complexity: O(m+n)
// Space complexity: O(m)

// The title is reprinted from licou official website:
// https://leetcode-cn.com/problems/intersection-of-two-arrays/
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