README_EN.md

349. Intersection of Two Arrays

中文文档

Description

Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any order.

 

Example 1:

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

Example 2:

Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
Output: [9,4]
Explanation: [4,9] is also accepted.

 

Constraints:

• 1 <= nums1.length, nums2.length <= 1000
• 0 <= nums1[i], nums2[i] <= 1000

Solutions

Python3

class Solution:
    def intersection(self, nums1: List[int], nums2: List[int]) -> List[int]:
        s1, s2 = set(nums1), set(nums2)
        return list(s1 & s2)

Java

class Solution {
    public int[] intersection(int[] nums1, int[] nums2) {
        Set<Integer> s1 = transfer(nums1);
        Set<Integer> s2 = transfer(nums2);
        s1.retainAll(s2);
        int[] output = new int[s1.size()];
        int i = 0;
        for (Integer e : s1) {
            output[i++] = e;
        }
        return output;
    }

    private Set<Integer> transfer(int[] nums) {
        Set<Integer> s = new HashSet<>();
        for (int e : nums) {
            s.add(e);
        }
        return s;
    }
}

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