Press "Enter" to skip to content

Intersection of Two Arrays-LeetCode#349

349.Intersection of Two Arrays

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

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]

Note:

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

思路:给定两个数组,编写一个函数来计算它们的交集。

使用Set集合不会存储重复元素的特性。先遍历其中一个数组存入Set集合,再遍历另一个数组在Set中查找是否存在,若存在添加到一个新的Set集合中。

代码如下:

public class IntersectionOfTwoArrays {
    private static int[] intersection(int[] nums1, int[] nums2) {
        Set<Integer> set1 = new HashSet<>();
        for (int i2 : nums1) {
            set1.add(i2);
        }

        Set<Integer> set2 = new HashSet<>();
        for (int i1 : nums2) {
            if (set1.contains(i1)) {
                set2.add(i1);
            }
        }

        int[] result = new int[set2.size()];
        int i = 0;
        for (int cell : set2) {
            result[i++] = cell;
        }
        return result;
    }

    public static void main(String[] args) {
        int[] nums1 = {4, 9, 5};
        int[] nums2 = {9, 4, 9, 8, 4};
        int[] res = IntersectionOfTwoArrays.intersection(nums1, nums2);
        for (int i : res) {
            System.out.println(i);
        }
    }
}

Be First to Comment

发表评论

电子邮件地址不会被公开。 必填项已用*标注