Solution3.java

package SetBasicsAndBSTSet;

import java.util.ArrayList;
import java.util.TreeMap;

/**
 * @ Description: LeetCode 350题目
 * @ Date: Created in 23:16 20/07/2018
 * @ Author: Anthony_Duan
 */
public class Solution3 {
    public int[] intersect(int[] nums1, int[] nums2) {

        TreeMap<Integer, Integer> map = new TreeMap<>();
        for (int num :
                nums1) {
            if (!map.containsKey(num)) {
                map.put(num, 1);
            } else {
                map.put(num, map.get(num) + 1);
            }
        }

        ArrayList<Integer> list = new ArrayList<>();

        for (int num :
                nums2) {
            if (map.containsKey(num)) {
                list.add(num);
                map.put(num, map.get(num) - 1);
                if (map.get(num) == 0) {
                    map.remove(num);
                }
            }
        }

        int[] res = new int[list.size()];
        for (int i = 0; i < list.size(); i++) {
            res[i] = list.get(i);
        }
        return res;

    }
}