两个数组的交集 II

Problem:

350. 两个数组的交集 II

思路

哈希表，需要返回数组，Java涉及到了类型转换

Code

class Solution {public int[] intersect(int[] nums1, int[] nums2) {if (nums1.length > nums2.length) {return intersect(nums2, nums1);}Map<Integer, Integer> map = new HashMap<Integer, Integer>();for (int num : nums1) {int count = map.getOrDefault(num, 0) + 1;map.put(num, count);}int[] intersection = new int[nums1.length];int index = 0;for (int num : nums2) {int count = map.getOrDefault(num, 0);if (count > 0) {intersection[index++] = num;count--;if (count > 0) {map.put(num, count);} else {map.remove(num);}}}return Arrays.copyOfRange(intersection, 0, index);}
}