refactor 425

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_425.java

@@ -71,86 +71,90 @@ The output consists of two word squares. The order of output does not matter (ju
  */
 public class _425 {
 
-    /**Credit: https://discuss.leetcode.com/topic/63516/explained-my-java-solution-using-trie-126ms-16-16/2*/
-
-    class TrieNode {
-        List<String> startWith;
-        TrieNode[] children;
-
-        TrieNode() {
-            startWith = new ArrayList<>();
-            children = new TrieNode[26];
+    public static class Solution1 {
+        /**
+         * Credit: https://discuss.leetcode.com/topic/63516/explained-my-java-solution-using-trie-126ms-16-16/2
+         */
+
+        class TrieNode {
+            List<String> startWith;
+            TrieNode[] children;
+
+            TrieNode() {
+                startWith = new ArrayList<>();
+                children = new TrieNode[26];
+            }
         }
-    }
 
-    class Trie {
-        TrieNode root;
+        class Trie {
+            TrieNode root;
+
+            Trie(String[] words) {
+                root = new TrieNode();
+                for (String word : words) {
+                    TrieNode cur = root;
+                    for (char ch : word.toCharArray()) {
+                        int index = ch - 'a';
+                        if (cur.children[index] == null) {
+                            cur.children[index] = new TrieNode();
+                        }
+                        cur.children[index].startWith.add(word);
+                        cur = cur.children[index];
+                    }
+                }
+            }
 
-        Trie(String[] words) {
-            root = new TrieNode();
-            for (String word : words) {
+            List<String> findByPrefix(String prefix) {
+                List<String> ans = new ArrayList<>();
                 TrieNode cur = root;
-                for (char ch : word.toCharArray()) {
+                for (char ch : prefix.toCharArray()) {
                     int index = ch - 'a';
                     if (cur.children[index] == null) {
-                        cur.children[index] = new TrieNode();
+                        return ans;
                     }
-                    cur.children[index].startWith.add(word);
+
                     cur = cur.children[index];
                 }
+                ans.addAll(cur.startWith);
+                return ans;
             }
         }
 
-        List<String> findByPrefix(String prefix) {
-            List<String> ans = new ArrayList<>();
-            TrieNode cur = root;
-            for (char ch : prefix.toCharArray()) {
-                int index = ch - 'a';
-                if (cur.children[index] == null) {
-                    return ans;
-                }
-
-                cur = cur.children[index];
+        public List<List<String>> wordSquares(String[] words) {
+            List<List<String>> ans = new ArrayList<>();
+            if (words == null || words.length == 0) {
+                return ans;
+            }
+            int len = words[0].length();
+            Trie trie = new Trie(words);
+            List<String> ansBuilder = new ArrayList<>();
+            for (String w : words) {
+                ansBuilder.add(w);
+                search(len, trie, ans, ansBuilder);
+                ansBuilder.remove(ansBuilder.size() - 1);
             }
-            ans.addAll(cur.startWith);
-            return ans;
-        }
-    }
 
-    public List<List<String>> wordSquares(String[] words) {
-        List<List<String>> ans = new ArrayList<>();
-        if (words == null || words.length == 0) {
             return ans;
         }
-        int len = words[0].length();
-        Trie trie = new Trie(words);
-        List<String> ansBuilder = new ArrayList<>();
-        for (String w : words) {
-            ansBuilder.add(w);
-            search(len, trie, ans, ansBuilder);
-            ansBuilder.remove(ansBuilder.size() - 1);
-        }
-
-        return ans;
-    }
 
-    private void search(int len, Trie trie, List<List<String>> ans,
-                        List<String> ansBuilder) {
-        if (ansBuilder.size() == len) {
-            ans.add(new ArrayList<>(ansBuilder));
-            return;
-        }
+        private void search(int len, Trie trie, List<List<String>> ans,
+                            List<String> ansBuilder) {
+            if (ansBuilder.size() == len) {
+                ans.add(new ArrayList<>(ansBuilder));
+                return;
+            }
 
-        int idx = ansBuilder.size();
-        StringBuilder prefixBuilder = new StringBuilder();
-        for (String s : ansBuilder) {
-            prefixBuilder.append(s.charAt(idx));
-        }
-        List<String> startWith = trie.findByPrefix(prefixBuilder.toString());
-        for (String sw : startWith) {
-            ansBuilder.add(sw);
-            search(len, trie, ans, ansBuilder);
-            ansBuilder.remove(ansBuilder.size() - 1);
+            int idx = ansBuilder.size();
+            StringBuilder prefixBuilder = new StringBuilder();
+            for (String s : ansBuilder) {
+                prefixBuilder.append(s.charAt(idx));
+            }
+            List<String> startWith = trie.findByPrefix(prefixBuilder.toString());
+            for (String sw : startWith) {
+                ansBuilder.add(sw);
+                search(len, trie, ans, ansBuilder);
+                ansBuilder.remove(ansBuilder.size() - 1);
+            }
         }
     }
 

src/test/java/com/fishercoder/_425Test.java

@@ -1,26 +1,25 @@
 package com.fishercoder;
 
+import com.fishercoder.common.utils.CommonUtils;
 import com.fishercoder.solutions._425;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.List;
 
-/**
- * Created by stevesun on 6/3/17.
- */
 public class _425Test {
-    private static _425 test;
+    private static _425.Solution1 solution1;
     private static String[] words;
 
     @BeforeClass
     public static void setup() {
-        test = new _425();
+        solution1 = new _425.Solution1();
     }
 
     @Test
     public void test1() {
         words = new String[]{"area", "lead", "wall", "lady", "ball"};
-        List<List<String>> result = test.wordSquares(words);
+        List<List<String>> result = solution1.wordSquares(words);
+        CommonUtils.printListList(result);
     }
 }