feat: add java solution to lc problem: No.1486.XOR Operation in an Array (#543)

Author: 0xcaffebabe

solution/1400-1499/1486.XOR Operation in an Array/README.md

@@ -75,7 +75,15 @@ class Solution:
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
-
+class Solution {
+  public int xorOperation(int n, int start) {
+    int ret = start;
+    for (int i = 1; i < n; i++) {
+      ret = ret ^ (start + (i << 1));
+    }
+    return ret;
+  }
+}
 ```
 
 ### **...**

solution/1400-1499/1486.XOR Operation in an Array/README_EN.md

@@ -108,7 +108,15 @@ class Solution:
 ### **Java**
 
 ```java
-
+class Solution {
+  public int xorOperation(int n, int start) {
+    int ret = start;
+    for (int i = 1; i < n; i++) {
+      ret = ret ^ (start + (i << 1));
+    }
+    return ret;
+  }
+}
 ```
 
 ### **...**

solution/1400-1499/1486.XOR Operation in an Array/Solution.java

@@ -0,0 +1,9 @@
+class Solution {
+  public int xorOperation(int n, int start) {
+    int ret = start;
+    for (int i = 1; i < n; i++) {
+      ret = ret ^ (start + (i << 1));
+    }
+    return ret;
+  }
+}