refactor 93

Author: fishercoder1534

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

@@ -3,60 +3,50 @@
 import java.util.ArrayList;
 import java.util.List;
 
-/**
- * 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)
- */
 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);
-      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(".");
+    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);
+            return allValidIpAddresses;
         }
-        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;
+        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;
+            }
+
+            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);
+            }
         }
-        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);
+        private boolean isValid(String oneByte) {
+            if (oneByte.charAt(0) == '0') {
+                return oneByte.equals("0");
+            }
+            int num = Integer.valueOf(oneByte);
+            return (num >= 0 && num < 256);
+        }
     }
-  }
 }