refactor 421

fishercoder1534 · fishercoder1534 · commit d85988df925f · 2019-03-23T08:15:15.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_421.java b/src/main/java/com/fishercoder/solutions/_421.java
@@ -20,35 +20,37 @@ Could you do this in O(n) runtime?
  */
 public class _421 {
 
-    //credit: https://discuss.leetcode.com/topic/63213/java-o-n-solution-using-bit-manipulation-and-hashmap/7
-    public int findMaximumXOR(int[] nums) {
-        int max = 0;
-        int mask = 0;
-        for (int i = 31; i >= 0; i--) {
-            mask |= (1 << i);//the mask will grow like this: 100...000, 110...000, 111...000 to 111...111, each time, we only get the most left part of all numbers in the given array
-            System.out.println("mask = " + Integer.toBinaryString(mask));
-            Set<Integer> set = new HashSet<>();
-            for (int num : nums) {
-                System.out.println("num = " + Integer.toBinaryString(num));
-                set.add(num & mask);
-                System.out.println("mask & num = " + Integer.toBinaryString(mask & num));
-            }
+    public static class Solution1 {
+        //credit: https://discuss.leetcode.com/topic/63213/java-o-n-solution-using-bit-manipulation-and-hashmap/7
+        public int findMaximumXOR(int[] nums) {
+            int max = 0;
+            int mask = 0;
+            for (int i = 31; i >= 0; i--) {
+                mask |= (1 << i);//the mask will grow like this: 100...000, 110...000, 111...000 to 111...111, each time, we only get the most left part of all numbers in the given array
+                System.out.println("mask = " + Integer.toBinaryString(mask));
+                Set<Integer> set = new HashSet<>();
+                for (int num : nums) {
+                    System.out.println("num = " + Integer.toBinaryString(num));
+                    set.add(num & mask);
+                    System.out.println("mask & num = " + Integer.toBinaryString(mask & num));
+                }
 
-            int candidate = max | (1 << i);
-            System.out.println("candidate = " + Integer.toBinaryString(candidate));
-            /**Reason behind this: if a ^ prefix = candidate, then a ^ candidate = prefix, also prefix ^ candidate = a
-             * in this below code: we use this one: prefix ^ candidate = a*/
-            for (int prefix : set) {
-                System.out.println("candidate ^ prefix = " + Integer.toBinaryString(candidate ^ prefix));
-                if (set.contains(candidate ^ prefix)) {
-                    max = candidate;
+                int candidate = max | (1 << i);
+                System.out.println("candidate = " + Integer.toBinaryString(candidate));
+                /**Reason behind this: if a ^ prefix = candidate, then a ^ candidate = prefix, also prefix ^ candidate = a
+                 * in this below code: we use this one: prefix ^ candidate = a*/
+                for (int prefix : set) {
+                    System.out.println("candidate ^ prefix = " + Integer.toBinaryString(candidate ^ prefix));
+                    if (set.contains(candidate ^ prefix)) {
+                        max = candidate;
+                    }
                 }
+                System.out.println("max = " + max);
+                System.out.println("i = " + i);
+                System.out.println("===============================================");
             }
-            System.out.println("max = " + max);
-            System.out.println("i = " + i);
-            System.out.println("===============================================");
+            return max;
         }
-        return max;
     }
 
 }
diff --git a/src/test/java/com/fishercoder/_421Test.java b/src/test/java/com/fishercoder/_421Test.java
@@ -6,25 +6,22 @@
 
 import static junit.framework.Assert.assertEquals;
 
-/**
- * Created by fishercoder on 4/28/17.
- */
 public class _421Test {
-    private static _421 test;
+    private static _421.Solution1 solution1;
     private static int expected;
     private static int actual;
     private static int[] nums;
 
     @BeforeClass
     public static void setup() {
-        test = new _421();
+        solution1 = new _421.Solution1();
     }
 
     @Test
     public void test1() {
         nums = new int[]{3, 10, 5, 25, 2, 8};
         expected = 28;
-        actual = test.findMaximumXOR(nums);
+        actual = solution1.findMaximumXOR(nums);
         assertEquals(expected, actual);
     }
 }
