import java.util.*; public class Main { public static void main(String[] args){ Scanner sc = new Scanner(System.in); int count = sc.nextInt(); int[] arr = new int[count]; int res = 0; for(int i=0;i<count;i++){ arr[i] = sc.nextInt(); res ^= arr[i]; } System.out.println(res); } }
import java.util.Scanner; import java.util.Arrays; public class Main{ public static void main(String[] args){ Scanner sc=new Scanner(System.in); int n=sc.nextInt(); int[] arr=new int[n]; for(int i=0;i<n;i++){ arr[i]=sc.nextInt(); } Arrays.sort(arr); for(int i=0;i<n-1;){ if(arr[i]!=arr[i+1]){ System.out.print(arr[i]); break; } i=i+2; } } }
public static void test(int[] data) { //题解: 例如 5^5=0。 int flag = 0; for (int ele : data) { flag = flag ^ ele; } System.out.println(flag); }