方法一：List转Int数组 （逐个复制）

List<Integer> list = new ArrayList<Integer>();
//LinkedList<Integer> list = new LinkedList<Integer>();list.add(1);list.add(2);int count = list.size();int[] aux = new int[count];for(int i = 0; i < count; i++){aux[i] = list.poll();}return aux;

方法二：使用函数Arrays.copyOfRange

int length1 = nums1.length, length2 = nums2.length;
int[] intersection = new int[Math.min(length1, length2)];
return Arrays.copyOfRange(intersection, 0, index);