import java.util.*; public class Solution { /** * * @param arr int整型一维数组 the array * @return int整型 */ public static int maxLength (int[] arr) { // write code here int maxLength = 0; LinkedList<Integer> list = new LinkedList<>(); for(int i = 0 ; i < arr.length ; i++){ while (list.contains(arr[i])){ list.removeFirst(); } list.add(arr[i]); if (list.size() > maxLength){ maxLength = list.size(); } } return maxLength; } public static void main(String[] args) { int[] arr = {2,2,3,4,3}; System.out.println(maxLength(arr)); } }