refactor(tests): update solution references in test cases

* Replace references to StringProblemsSolution with MediumStringProblemsSolution for consistency

Signed-off-by: Zahid Khan <xahiidkhan@gmail.com>

Author: ZahidFKhan

src/test/java/com/github/streams/practice/b_medium_problems/numbers/B_SumOfUniqueNumbers.java

@@ -1,10 +1,12 @@
 package com.github.streams.practice.b_medium_problems.numbers;
 
-import java.util.List;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+
 /**
  * Calculates the sum of unique elements in an array. <br>
  * Example: <br>
@@ -17,8 +19,8 @@ class B_SumOfUniqueNumbers {
   @Disabled
   void testSumOfUniqueDigitsTest() {
     final var input = List.of(5, 6, 7, 8, 5, 5, 8, 8, 7);
-    var mySolution = MediumNumbersProblemSolution.sumOfUniqueNumbers(input);
-    var yourSolution = List.of();
+    final var mySolution = MediumNumbersProblemSolution.sumOfUniqueNumbers(input);
+    final var yourSolution = ThreadLocalRandom.current().nextLong();
 
     Assertions.assertEquals(mySolution, yourSolution);
   }

src/test/java/com/github/streams/practice/b_medium_problems/numbers/MediumNumbersProblemSolution.java

@@ -37,6 +37,7 @@ public static <T> List<T> getUniqueNumberFromList(List<T> input) {
     return input.stream().distinct().toList();
   }
 
+  // Alternative to Easy: uses a primitive IntStream to avoid boxing overhead.
   public static long sumOfNumbers(List<Integer> input) {
     return input.stream().mapToInt(Integer::intValue).sum();
   }
@@ -90,6 +91,8 @@ public static double meanOfNumbers(List<Integer> input) {
     return input.stream().mapToInt(Integer::intValue).average().orElse(0);
   }
 
+  // Alternative to Easy: keys are range-starts (0, 10, 20…) instead of raw quotients (0, 1, 2…).
+  // Compare both outputs to understand the difference in grouping strategies.
   public static Map<Integer, List<Integer>> groupingOfNumbers(List<Integer> randomIntegers) {
     return randomIntegers.stream().collect(Collectors.groupingBy(e -> (e / 10) * 10));
   }

src/test/java/com/github/streams/practice/b_medium_problems/strings/A_MatchesNoOfVowelsTest.java

@@ -38,7 +38,7 @@ void testAM_MaxNoOfVowelsTest() {
     var input = "The quick brown fox jumps right over the little lazy dog.";
     final var length = 2;
 
-    var mySolution = StringProblemsSolution.getMatchesVowels(input, length);
+    final var mySolution = MediumStringProblemsSolution.getMatchesVowels(input, length);
     var yourSolution = List.of();
     Assertions.assertEquals(mySolution, yourSolution);
   }

src/test/java/com/github/streams/practice/b_medium_problems/strings/B_LargestWordTest.java

@@ -16,13 +16,13 @@ class B_LargestWordTest {
    * </pre>
    *
    * @author ZahidKhan
-   * @see StringProblemsSolution#findLargestWordInTheString(String)
+   * @see MediumStringProblemsSolution#findLargestWordInTheString(String)
    */
   @Test
   @Disabled()
   public void findLargestWordInTheString() {
     final String input = "I am interested123455 to grow in my organization";
-    final String mySolution = StringProblemsSolution.findLargestWordInTheString(input);
+    final String mySolution = MediumStringProblemsSolution.findLargestWordInTheString(input);
 
     String yourSolution = null;
 

src/test/java/com/github/streams/practice/b_medium_problems/strings/C_LengthOfCityTest.java

@@ -25,7 +25,7 @@ class C_LengthOfCityTest {
   @Disabled
   void testCalculateLengthOfEachCityTest() {
     final var cities = List.of("Mumbai", "Munnar", "Chennai", "Hyderabad");
-    final var mySolution = StringProblemsSolution.findLengthOfEachCityAlongWithSize(cities);
+    final var mySolution = MediumStringProblemsSolution.findLengthOfEachCityAlongWithSize(cities);
 
     final Map<String, Integer> yourSolution = new HashMap<>();
     Assertions.assertEquals(yourSolution, mySolution);

src/test/java/com/github/streams/practice/b_medium_problems/strings/D_NumberOfOccurencesOfEachCharacterTest.java

@@ -11,7 +11,7 @@ class D_NumberOfOccurencesOfEachCharacterTest {
   @Disabled("Remove This Once you Complete The Exercise")
   void numberOfOccurencesOfEachCharacter() {
     final String input = "the quick brown fox jumps right over the little lazy dog little";
-    final var mySolution = StringProblemsSolution.findOccurenceOfCharacter(input);
+    final var mySolution = MediumStringProblemsSolution.findOccurenceOfCharacter(input);
     final Map<Character, Long> yourSolution = null;
 
     assertEquals(mySolution, yourSolution);

src/test/java/com/github/streams/practice/b_medium_problems/strings/E_NumberOfOccurencesOfEachWordTest.java

@@ -11,7 +11,7 @@ class E_NumberOfOccurencesOfEachWordTest {
   @Disabled
   public void numberOfOccurencesOfEachWord() {
     final var input = "the quick brown fox jumps right over the little lazy dog little";
-    final Map<String, Long> mySolution = StringProblemsSolution.numberOfOccurenceOfEachWord(input);
+    final Map<String, Long> mySolution = MediumStringProblemsSolution.numberOfOccurenceOfEachWord(input);
 
     Map<String, Long> yourSolution = Map.of();
     assertEquals(mySolution, yourSolution);

src/test/java/com/github/streams/practice/b_medium_problems/strings/F_ConcatenationOfStrings.java

@@ -14,7 +14,7 @@ class F_ConcatenationOfStrings {
   @Disabled
   void testConcatenationOfStrings() {
     List<String> input = List.of("Hellow", "World", "Hello", "World");
-    final var mySolution = StringProblemsSolution.concatenateStrings(input);
+    final var mySolution = MediumStringProblemsSolution.concatenateStrings(input);
     final var yourSolution = "";
 
     Assertions.assertEquals(mySolution, yourSolution);

src/test/java/com/github/streams/practice/b_medium_problems/strings/G_RemoveDuplicateCharactersTest.java

@@ -11,7 +11,7 @@ class G_RemoveDuplicateCharactersTest {
   public void testRemoveDuplicates() {
     final String input = "dabfcadef";
     final String yourSolution = "";
-    final String mySolution = StringProblemsSolution.getUniqueCharacters(input);
+    final String mySolution = MediumStringProblemsSolution.getUniqueCharacters(input);
 
     assertEquals(mySolution, yourSolution);
   }

src/test/java/com/github/streams/practice/b_medium_problems/strings/H_ReverseStringWithSpecialCharactersTest.java

@@ -22,7 +22,7 @@ class H_ReverseStringWithSpecialCharactersTest {
   @Disabled
   void testReverseStringWithSpecialCharactersTest() {
     var input = "Hello world! This is a test. 😅";
-    var mySolution = StringProblemsSolution.reverseStringWithSpecialCharacters(input);
+    var mySolution = MediumStringProblemsSolution.reverseStringWithSpecialCharacters(input);
 
     var yourSolution = "";