Update WordLadderTest.java & WordLadder.java (TheAlgorithms#3674)

Author: TaranjeetSinghKalsi

src/main/java/com/thealgorithms/strings/WordLadder.java

@@ -34,21 +34,8 @@
     beginWord != endWord
     All the words in wordList are unique.
  */
-class WordLadder {
-
-    /**
-     * Driver Code
-     */
-    public static void main(String[] args) {
-        String beginWord = "hit";
-        String endWord = "cog";
-        String words[] = { "hot", "dot", "dog", "lot", "log", "cog" };
-        List<String> wordList = Arrays.asList(words);
 
-        System.out.println(
-            "Ladder Length: " + ladderLength(beginWord, endWord, wordList)
-        );
-    }
+class WordLadder {
 
     /**
      * This function finds the ladderLength
@@ -60,11 +47,7 @@ public static void main(String[] args) {
      * @return ladderLength: This function will return the ladderLength(level)
      * if the endword is there. Otherwise, will return the length as 0.
      */
-    public static int ladderLength(
-        String beginWord,
-        String endWord,
-        List<String> wordList
-    ) {
+    public static int ladderLength(String beginWord, String endWord, List<String> wordList) {
         HashSet<String> set = new HashSet();
         for (String word : wordList) {
             set.add(word);

src/test/java/com/thealgorithms/strings/WordLadderTest.java

@@ -1,17 +1,38 @@
 package com.thealgorithms.strings;
 
 import static org.junit.jupiter.api.Assertions.*;
-
 import org.junit.jupiter.api.Test;
 import java.util.*;
 
 public class WordLadderTest {
 
     @Test
     public void testWordLadder() {
-        String words1[] = { "hot", "dot", "dog", "lot", "log", "cog" };
-        assertEquals(5, WordLadder.ladderLength("hit", "cog", Arrays.asList(words1)));
-        String words2[] = { "hot", "dot", "dog", "lot", "log" };
-        assertEquals(0, WordLadder.ladderLength("hit", "cog", Arrays.asList(words2)));
+       
+        /**
+         * Test 1:
+         * Input: beginWord = "hit", endWord = "cog", wordList =
+         * ["hot","dot","dog","lot","log","cog"]
+         * Output: 5
+         * Explanation: One shortest transformation sequence is
+         * "hit" -> "hot" -> "dot" -> "dog" -> cog"
+         * which is 5 words long.
+         */
+
+        List<String> wordList1 = Arrays.asList("hot", "dot", "dog", "lot", "log", "cog");
+        assertEquals(WordLadder.ladderLength("hit", "cog", wordList1), 5);
+
+        /**
+         * Test 2:
+         * Input: beginWord = "hit", endWord = "cog", wordList =
+         * ["hot","dot","dog","lot","log"]
+         * Output: 0
+         * Explanation: The endWord "cog" is not in wordList,
+         * therefore there is no valid transformation sequence.
+         */
+
+        List<String> wordList2 = Arrays.asList("hot", "dot", "dog", "lot", "log");
+        assertEquals(WordLadder.ladderLength("hit", "cog", wordList2), 0);
+
      }
 }