refactor 93

Author: fishercoder1534

README.md

@@ -596,7 +596,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |96|[Unique Binary Search Trees](https://leetcode.com/problems/unique-binary-search-trees/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_96.java) | O(n^2) | O(n) | |Medium | Recursion, DP
 |95|[Unique Binary Search Trees II](https://leetcode.com/problems/unique-binary-search-trees-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_95.java) | O(?) | O(?) | |Medium | Recursion
 |94|[Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_94.java)| O(n)|O(h) | |Medium| Binary Tree
-|93|[Restore IP Addresses](https://leetcode.com/problems/restore-ip-addresses/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_93.java)| O(1)|O(1) | |Medium | Backtracking
+|93|[Restore IP Addresses](https://leetcode.com/problems/restore-ip-addresses/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_93.java)| O(?)|O(?) | |Medium | Backtracking
 |92|[Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_92.java)| O(n)|O(1) | |Medium
 |91|[Decode Ways](https://leetcode.com/problems/decode-ways/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_91.java)| O(n)|O(n) | |Medium| DP
 |90|[Subsets II](https://leetcode.com/problems/subsets-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_90.java)|O(n^2) |O(1)||Medium|Backtracking

src/main/java/com/fishercoder/solutions/_93.java

@@ -6,56 +6,57 @@
 /**
  * 93. Restore IP Addresses
  *
- * Given a string containing only digits, restore it by returning all possible valid IP address combinations.
-
- For example:
- Given "25525511135",
-
- return ["255.255.11.135", "255.255.111.35"]. (Order does not matter)
+ * Given a string containing only digits, restore it by returning all possible valid IP address
+ * combinations.
+ *
+ * For example: Given "25525511135",
+ *
+ * return ["255.255.11.135", "255.255.111.35"]. (Order does not matter)
  */
 public class _93 {
 
+  public static class Solution1 {
     public List<String> restoreIpAddresses(String s) {
-        List<String> allValidIpAddresses = new ArrayList<>();
-        if (s == null || s.length() > 12 || s.length() < 4) {
-            return allValidIpAddresses;
-        }
-        backtracking(s, new ArrayList<>(), allValidIpAddresses, 0);
+      List<String> allValidIpAddresses = new ArrayList<>();
+      if (s == null || s.length() > 12 || s.length() < 4) {
         return allValidIpAddresses;
+      }
+      backtracking(s, new ArrayList<>(), allValidIpAddresses, 0);
+      return allValidIpAddresses;
     }
 
     private void backtracking(String s, ArrayList<String> bytes, List<String> result, int pos) {
-        if (bytes.size() == 4) {
-            if (pos != s.length()) {
-                return;
-            }
-            StringBuilder stringBuilder = new StringBuilder();
-            for (int i = 0; i < 4; i++) {
-                stringBuilder.append(bytes.get(i));
-                stringBuilder.append(".");
-            }
-            stringBuilder.setLength(stringBuilder.length() - 1);
-            result.add(stringBuilder.toString());
-            return;
+      if (bytes.size() == 4) {
+        if (pos != s.length()) {
+          return;
         }
-
-        for (int i = pos; i < pos + 4 && i < s.length(); i++) {
-            String oneByte = s.substring(pos, i + 1);
-            if (!isValid(oneByte)) {
-                continue;
-            }
-            bytes.add(oneByte);
-            backtracking(s, bytes, result, i + 1);
-            bytes.remove(bytes.size() - 1);
+        StringBuilder stringBuilder = new StringBuilder();
+        for (int i = 0; i < 4; i++) {
+          stringBuilder.append(bytes.get(i));
+          stringBuilder.append(".");
+        }
+        stringBuilder.setLength(stringBuilder.length() - 1);
+        result.add(stringBuilder.toString());
+        return;
+      }
+
+      for (int i = pos; i < pos + 4 && i < s.length(); i++) {
+        String oneByte = s.substring(pos, i + 1);
+        if (!isValid(oneByte)) {
+          continue;
         }
+        bytes.add(oneByte);
+        backtracking(s, bytes, result, i + 1);
+        bytes.remove(bytes.size() - 1);
+      }
     }
 
     private boolean isValid(String oneByte) {
-        if (oneByte.charAt(0) == '0') {
-            return oneByte.equals("0");
-        }
-        int num = Integer.valueOf(oneByte);
-        return (num >= 0 && num < 256);
+      if (oneByte.charAt(0) == '0') {
+        return oneByte.equals("0");
+      }
+      int num = Integer.valueOf(oneByte);
+      return (num >= 0 && num < 256);
     }
-
+  }
 }

src/test/java/com/fishercoder/_93Test.java

@@ -11,28 +11,25 @@
 import static junit.framework.Assert.assertEquals;
 
 public class _93Test {
-    private static _93 test;
-    private static List<String> expected;
-    private static List<String> actual;
-    private static String s;
+  private static _93.Solution1 solution1;
+  private static List<String> expected;
+  private static String s;
 
-    @BeforeClass
-    public static void setup() {
-        test = new _93();
-    }
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _93.Solution1();
+  }
 
-    @Before
-    public void setupForEachTest() {
-        expected = new ArrayList<>();
-        actual = new ArrayList<>();
-    }
+  @Before
+  public void setupForEachTest() {
+    expected = new ArrayList<>();
+  }
 
-    @Test
-    public void test1() {
-        s = "25525511135";
-        expected.add("255.255.11.135");
-        expected.add("255.255.111.35");
-        actual = test.restoreIpAddresses(s);
-        assertEquals(expected, actual);
-    }
+  @Test
+  public void test1() {
+    s = "25525511135";
+    expected.add("255.255.11.135");
+    expected.add("255.255.111.35");
+    assertEquals(expected, solution1.restoreIpAddresses(s));
+  }
 }