Add PhoneticAlphabetConverter (#5752)

Author: Hardvan

DIRECTORY.md

@@ -100,6 +100,7 @@
             * [OctalToBinary](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToBinary.java)
             * [OctalToDecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToDecimal.java)
             * [OctalToHexadecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToHexadecimal.java)
+            * [PhoneticAlphabetConverter](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/PhoneticAlphabetConverter.java)
             * [RgbHsvConversion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/RgbHsvConversion.java)
             * [RomanToInteger](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/RomanToInteger.java)
             * [TurkishToLatinConversion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/TurkishToLatinConversion.java)
@@ -740,6 +741,7 @@
             * [OctalToBinaryTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToBinaryTest.java)
             * [OctalToDecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToDecimalTest.java)
             * [OctalToHexadecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToHexadecimalTest.java)
+            * [PhoneticAlphabetConverterTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/PhoneticAlphabetConverterTest.java)
             * [RomanToIntegerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/RomanToIntegerTest.java)
             * [UnitConversionsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/UnitConversionsTest.java)
             * [UnitsConverterTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/UnitsConverterTest.java)

src/main/java/com/thealgorithms/conversions/PhoneticAlphabetConverter.java

@@ -0,0 +1,68 @@
+package com.thealgorithms.conversions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Converts text to the NATO phonetic alphabet.
+ * Examples:
+ * "ABC" -> "Alpha Bravo Charlie"
+ * "Hello" -> "Hotel Echo Lima Lima Oscar"
+ * "123" -> "One Two Three"
+ * "A1B2C3" -> "Alpha One Bravo Two Charlie Three"
+ *
+ * @author Hardvan
+ */
+public final class PhoneticAlphabetConverter {
+    private PhoneticAlphabetConverter() {
+    }
+
+    private static final Map<Character, String> PHONETIC_MAP = new HashMap<>();
+
+    static {
+        PHONETIC_MAP.put('A', "Alpha");
+        PHONETIC_MAP.put('B', "Bravo");
+        PHONETIC_MAP.put('C', "Charlie");
+        PHONETIC_MAP.put('D', "Delta");
+        PHONETIC_MAP.put('E', "Echo");
+        PHONETIC_MAP.put('F', "Foxtrot");
+        PHONETIC_MAP.put('G', "Golf");
+        PHONETIC_MAP.put('H', "Hotel");
+        PHONETIC_MAP.put('I', "India");
+        PHONETIC_MAP.put('J', "Juliett");
+        PHONETIC_MAP.put('K', "Kilo");
+        PHONETIC_MAP.put('L', "Lima");
+        PHONETIC_MAP.put('M', "Mike");
+        PHONETIC_MAP.put('N', "November");
+        PHONETIC_MAP.put('O', "Oscar");
+        PHONETIC_MAP.put('P', "Papa");
+        PHONETIC_MAP.put('Q', "Quebec");
+        PHONETIC_MAP.put('R', "Romeo");
+        PHONETIC_MAP.put('S', "Sierra");
+        PHONETIC_MAP.put('T', "Tango");
+        PHONETIC_MAP.put('U', "Uniform");
+        PHONETIC_MAP.put('V', "Victor");
+        PHONETIC_MAP.put('W', "Whiskey");
+        PHONETIC_MAP.put('X', "X-ray");
+        PHONETIC_MAP.put('Y', "Yankee");
+        PHONETIC_MAP.put('Z', "Zulu");
+        PHONETIC_MAP.put('0', "Zero");
+        PHONETIC_MAP.put('1', "One");
+        PHONETIC_MAP.put('2', "Two");
+        PHONETIC_MAP.put('3', "Three");
+        PHONETIC_MAP.put('4', "Four");
+        PHONETIC_MAP.put('5', "Five");
+        PHONETIC_MAP.put('6', "Six");
+        PHONETIC_MAP.put('7', "Seven");
+        PHONETIC_MAP.put('8', "Eight");
+        PHONETIC_MAP.put('9', "Nine");
+    }
+
+    public static String textToPhonetic(String text) {
+        StringBuilder phonetic = new StringBuilder();
+        for (char c : text.toUpperCase().toCharArray()) {
+            phonetic.append(PHONETIC_MAP.getOrDefault(c, String.valueOf(c))).append(" ");
+        }
+        return phonetic.toString().trim();
+    }
+}

src/test/java/com/thealgorithms/conversions/PhoneticAlphabetConverterTest.java

@@ -0,0 +1,21 @@
+package com.thealgorithms.conversions;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class PhoneticAlphabetConverterTest {
+
+    @Test
+    public void testTextToPhonetic() {
+        assertEquals("Alpha Bravo", PhoneticAlphabetConverter.textToPhonetic("AB"));
+        assertEquals("Alpha Bravo Charlie", PhoneticAlphabetConverter.textToPhonetic("ABC"));
+        assertEquals("Alpha One Bravo Two Charlie Three", PhoneticAlphabetConverter.textToPhonetic("A1B2C3"));
+        assertEquals("Hotel Echo Lima Lima Oscar", PhoneticAlphabetConverter.textToPhonetic("Hello"));
+        assertEquals("One Two Three", PhoneticAlphabetConverter.textToPhonetic("123"));
+        assertEquals("Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine",
+            PhoneticAlphabetConverter.textToPhonetic("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"));
+        assertEquals("Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine",
+            PhoneticAlphabetConverter.textToPhonetic("abcdefghijklmnopqrstuvwxyz0123456789"));
+    }
+}