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.

public class Solution {
    public int[] intersect(int[] nums1, int[] nums2) {
        Map s=new HashMap<>();
        List q=new ArrayList<>();
        for(int i:nums1){
            s.put(i,s.getOrDefault(i,0)+1);
        }
        for(int i:nums2){
            if(s.containsKey(new Integer(i))){
                if(s.get(i)-1<0)
                    s.remove(i);
                else {
                    s.put(i,s.get(i)-1);
                    q.add(i);
                }
            }
        }
        int[] result=new int[q.size()];
        for(int i=0;i

这是使用HashMap集合的方法解决问题，还有一种方式是首先通过排序将数组排序，然后根据大小顺序依次输出

public class Solution {
    public int[] intersect(int[] nums1, int[] nums2) {
           
        Arrays.sort(nums1);
        Arrays.sort(nums2);
        int[] flag=new int[nums1.length];
        int z=0;
        for(int i=0,j=0;inums2[j]) j++;
            else {
                flag[z]=nums1[i];
                i++;
                z++;
                j++;
            }
        }
        int[] result=new int[z];
        System.arraycopy(flag,0,result,0,z);
        return result;
    }
}