LeetCode oj 349. Intersection of Two Arrays（HashSet）

349. Intersection of Two Arrays

 

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

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

Note:

• Each element in the result must be unique.
• The result can be in any order.

给你两个数组，求两个数组中重复的元素

一直在用C++写ACM题，对java类库不是很熟悉，知道应该用set写，但是不会用hashset。。。。于是纯暴力写了一个，不过时间复杂度还好，A了之后学了一下set用法，一起放到这里

暴力解法：

public class Solution {
    public int[] intersection(int[] nums1, int[] nums2) {
        int len1 = nums1.length;
        int len2 = nums2.length;
        int hash1[] = new int [65535];
        int hash2[] = new int [65535];
        for(int i=0;i

HashSet：

public class Solution {
    public int[] intersection(int[] nums1, int[] nums2) {
        HashSetset = new HashSet();
        int len1 = nums1.length;
        int len2 = nums2.length;
        for(int i=0;ilist = new ArrayList();
        for(int i=0;i