更新day1/test2

day1/test2

+package day1;
+import javax.swing.plaf.synth.SynthOptionPaneUI;
+import java.util.Random;
+import java.util.Arrays;
+public class test2 {
+    public static void main(String [] args){
+        int N=11;
+        int M=(N-1)/2;
+        int[] arr=new int [N];
+        for (int i = 0; i < M; i++) {
+            arr[i]=i+1;
+            arr[i+M]=i+1;
+        }
+        arr[N-1]=new Random().nextInt(M)+M+1;
+        int a=new Random().nextInt(M);
+        int swith=arr[a];
+        arr[a]=arr[N-1];
+        arr[N-1]=swith;
+        System.out.println(Arrays.toString(arr));
+        int x=0;
+        for (int i = 0; i < N; i++) {
+            x=x^arr[i];
+        }
+        System.out.println("x="+x);
+        System.out.println("x1="+new Random().nextInt(2));
+    }
+
+}
+