update 249

Author: fishercoder1534

Diff for: src/main/java/com/fishercoder/solutions/_249.java

@@ -15,10 +15,17 @@ public List<List<String>> groupStrings(String[] strings) {
             Map<String, List<String>> map = new HashMap<>();
 
             for (String word : strings) {
+                //calculate the representative/key that's unique for the entire group
+                //i.e. if the two string belong to the same group, after shifting n times, they all will end up having the same key
+                // abc -> 2021
+                // xyz -> 2021
+                // acef -> 212324
                 String key = "";
                 int offset = word.charAt(0) - 'a';
                 for (int i = 1; i < word.length(); i++) {
-                    key += (word.charAt(i) - offset + 26) % 26;
+                    char c = word.charAt(i);
+                    int offsetForThisChar = (c - offset + 26) % 26;
+                    key += offsetForThisChar;
                 }
 
                 if (!map.containsKey(key)) {
@@ -28,7 +35,6 @@ public List<List<String>> groupStrings(String[] strings) {
             }
 
             for (List<String> list : map.values()) {
-                Collections.sort(list);
                 result.add(list);
             }
 

Diff for: src/test/java/com/fishercoder/_249Test.java

@@ -0,0 +1,27 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._249;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class _249Test {
+    private static _249.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _249.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        List<List<String>> expected = Arrays.asList(Arrays.asList("acef"), Arrays.asList("a", "z"), Arrays.asList("abc", "bcd", "xyz"), Arrays.asList("az", "ba"));
+        List<List<String>> actual = solution1.groupStrings(new String[]{"abc", "bcd", "acef", "xyz", "az", "ba", "a", "z"});
+        assertTrue(expected.containsAll(actual));
+        assertTrue(actual.containsAll(expected));
+    }
+}