refactor 214

fishercoder1534 · fishercoder1534 · commit a12882deb345 · 2018-09-23T08:00:30.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_214.java b/src/main/java/com/fishercoder/solutions/_214.java
@@ -2,6 +2,7 @@
 
 /**
  214. Shortest Palindrome
+
  Given a string S, you are allowed to convert it to a palindrome
  by adding characters in front of it.
  Find and return the shortest palindrome you can find by performing this transformation.
@@ -11,54 +12,55 @@
  Given "aacecaaa", return "aaacecaaa".
 
  Given "abcd", return "dcbabcd".
-
-
  */
 public class _214 {
 
-    /**credit: https://discuss.leetcode.com/topic/27261/clean-kmp-solution-with-super-detailed-explanation*/
-    /**TODO: read it explanation and understand KMP completely.*/
-    public String shortestPalindrome(String s) {
-        String temp = s + "#" + new StringBuilder(s).reverse().toString();
-        int[] table = getTable(temp);
-        //get the maximum palin part in s starts from 0
-        return new StringBuilder(s.substring(table[table.length - 1])).reverse().toString() + s;
-    }
+    public static class Solution1 {
+        /**credit: https://discuss.leetcode.com/topic/27261/clean-kmp-solution-with-super-detailed-explanation*/
+        /**
+         * TODO: read it explanation and understand KMP completely.
+         */
+        public String shortestPalindrome(String s) {
+            String temp = s + "#" + new StringBuilder(s).reverse().toString();
+            int[] table = getTable(temp);
+            //get the maximum palin part in s starts from 0
+            return new StringBuilder(s.substring(table[table.length - 1])).reverse().toString() + s;
+        }
 
-    public int[] getTable(String s) {
-        //get lookup table
-        int[] table = new int[s.length()];
+        public int[] getTable(String s) {
+            //get lookup table
+            int[] table = new int[s.length()];
 
-        //pointer that points to matched char in prefix part
-        int index = 0;
-        //skip index 0, we will not match a string with itself
-        for (int i = 1; i < s.length(); i++) {
-            if (s.charAt(index) == s.charAt(i)) {
-                //we can extend match in prefix and postfix
-                table[i] = table[i - 1] + 1;
-                index++;
-            } else {
-                //match failed, we try to match a shorter substring
+            //pointer that points to matched char in prefix part
+            int index = 0;
+            //skip index 0, we will not match a string with itself
+            for (int i = 1; i < s.length(); i++) {
+                if (s.charAt(index) == s.charAt(i)) {
+                    //we can extend match in prefix and postfix
+                    table[i] = table[i - 1] + 1;
+                    index++;
+                } else {
+                    //match failed, we try to match a shorter substring
 
-                //by assigning index to table[i-1], we will shorten the match string length, and jump to the
-                //prefix part that we used to match postfix ended at i - 1
-                index = table[i - 1];
+                    //by assigning index to table[i-1], we will shorten the match string length, and jump to the
+                    //prefix part that we used to match postfix ended at i - 1
+                    index = table[i - 1];
 
-                while (index > 0 && s.charAt(index) != s.charAt(i)) {
-                    //we will try to shorten the match string length until we revert to the beginning of match (index 1)
-                    index = table[index - 1];
-                }
+                    while (index > 0 && s.charAt(index) != s.charAt(i)) {
+                        //we will try to shorten the match string length until we revert to the beginning of match (index 1)
+                        index = table[index - 1];
+                    }
 
-                //when we are here may either found a match char or we reach the boundary and still no luck
-                //so we need check char match
-                if (s.charAt(index) == s.charAt(i)) {
-                    //if match, then extend one char
-                    index++;
+                    //when we are here may either found a match char or we reach the boundary and still no luck
+                    //so we need check char match
+                    if (s.charAt(index) == s.charAt(i)) {
+                        //if match, then extend one char
+                        index++;
+                    }
+                    table[i] = index;
                 }
-                table[i] = index;
             }
+            return table;
         }
-        return table;
     }
-
 }
