test: add LeetCode example test cases for leetcode 2828

docs/EASY.md

@@ -40,7 +40,7 @@ Total: 36 problems solved
 | 2315 | [Count Asterisks](https://leetcode.com/problems/count-asterisks/) | [CountAsterisks2315.java](../src/main/java/com/leetcode/easy/CountAsterisks2315.java) | [CountAsterisks2315Test.java](../src/test/java/com/leetcode/easy/CountAsterisks2315Test.java) |
 | 2469 | [Convert the Temperature](https://leetcode.com/problems/convert-the-temperature/) | [ConvertTheTemperature2469.java](../src/main/java/com/leetcode/easy/ConvertTheTemperature2469.java) | [ConvertTheTemperature2469Test.java](../src/test/java/com/leetcode/easy/ConvertTheTemperature2469Test.java) |
 | 2798 | [Number of Employees Who Met the Target](https://leetcode.com/problems/number-of-employees-who-met-the-target/) | [NumberOfEmployeesWhoMetTheTarget2798.java](../src/main/java/com/leetcode/easy/NumberOfEmployeesWhoMetTheTarget2798.java) | [NumberOfEmployeesWhoMetTheTarget2798Test.java](../src/test/java/com/leetcode/easy/NumberOfEmployeesWhoMetTheTarget2798Test.java) |
-| 2828 | [Check If A String Is An Acronym Of Words](https://leetcode.com/problems/check-if-a-string-is-an-acronym-of-words/) | [CheckIfAStringIsAnAcronymOfWords2828.java](../src/main/java/com/leetcode/easy/CheckIfAStringIsAnAcronymOfWords2828.java) | |
+| 2828 | [Check If A String Is An Acronym Of Words](https://leetcode.com/problems/check-if-a-string-is-an-acronym-of-words/) | [CheckIfAStringIsAnAcronymOfWords2828.java](../src/main/java/com/leetcode/easy/CheckIfAStringIsAnAcronymOfWords2828.java) | [CheckIfAStringIsAnAcronymOfWords2828Test.java](../src/test/java/com/leetcode/easy/CheckIfAStringIsAnAcronymOfWords2828Test.java) |
 | 3289 | [The Two Sneaky Numbers of Digitville](https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville/) | [TheTwoSneakyNumbersOfDigitville3289.java](../src/main/java/com/leetcode/easy/TheTwoSneakyNumbersOfDigitville3289.java) | [TheTwoSneakyNumbersOfDigitville3289Test.java](../src/test/java/com/leetcode/easy/TheTwoSneakyNumbersOfDigitville3289Test.java) |
 
 ---

src/test/java/com/leetcode/easy/CheckIfAStringIsAnAcronymOfWords2828Test.java

@@ -0,0 +1,50 @@
+package com.leetcode.easy;
+
+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.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class CheckIfAStringIsAnAcronymOfWords2828Test {
+    private CheckIfAStringIsAnAcronymOfWords2828 solution;
+
+    @BeforeEach
+    void setUp() {
+        solution = new CheckIfAStringIsAnAcronymOfWords2828();
+    }
+
+    @Test
+    void testIsAcronym_Example1_ValidAcronym() {
+        // Input: words = ["alice","bob","charlie"], s = "abc"
+        // First characters: 'a', 'b', 'c' -> "abc"
+        List<String> words = Arrays.asList("alice", "bob", "charlie");
+        String s = "abc";
+
+        assertTrue(solution.isAcronym(words, s));
+    }
+
+    @Test
+    void testIsAcronym_Example2_LengthMismatch() {
+        // Input: words = ["an","apple"], s = "a"
+        // First characters: 'a', 'a' -> "aa" (length 2)
+        // s = "a" (length 1), so cannot match
+        List<String> words = Arrays.asList("an", "apple");
+        String s = "a";
+
+        assertFalse(solution.isAcronym(words, s));
+    }
+
+    @Test
+    void testIsAcronym_Example3_LongAcronym() {
+        // Input: words = ["never","gonna","give","up","on","you"], s = "ngguoy"
+        // First characters: 'n', 'g', 'g', 'u', 'o', 'y' -> "ngguoy"
+        List<String> words = Arrays.asList("never", "gonna", "give", "up", "on", "you");
+        String s = "ngguoy";
+
+        assertTrue(solution.isAcronym(words, s));
+    }
+}