diff --git a/DIRECTORY.md b/DIRECTORY.md index 3d5b2bf61d6a..20c48ce8ca46 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -64,12 +64,15 @@ * [AffineCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AffineCipher.java) * [AtbashCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AtbashCipher.java) * [Autokey](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Autokey.java) + * [BaconianCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/BaconianCipher.java) * [Blowfish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Blowfish.java) * [Caesar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Caesar.java) * [ColumnarTranspositionCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java) * [DES](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/DES.java) + * [DiffieHellman](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/DiffieHellman.java) * [ECC](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ECC.java) * [HillCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/HillCipher.java) + * [MonoAlphabetic](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/MonoAlphabetic.java) * [PlayfairCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/PlayfairCipher.java) * [Polybius](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Polybius.java) * [ProductCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ProductCipher.java) @@ -311,6 +314,8 @@ * [ConvexHull](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/ConvexHull.java) * [GrahamScan](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/GrahamScan.java) * [Point](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/Point.java) + * graph + * [StronglyConnectedComponentOptimized](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/graph/StronglyConnectedComponentOptimized.java) * greedyalgorithms * [ActivitySelection](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/ActivitySelection.java) * [BinaryAddition](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/BinaryAddition.java) @@ -564,6 +569,7 @@ * [UnionFind](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UnionFind.java) * [UpperBound](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UpperBound.java) * sorts + * [AdaptiveMergeSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java) * [BeadSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BeadSort.java) * [BinaryInsertionSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BinaryInsertionSort.java) * [BitonicSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BitonicSort.java) @@ -603,6 +609,7 @@ * [SortUtils](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/SortUtils.java) * [SortUtilsRandomGenerator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/SortUtilsRandomGenerator.java) * [SpreadSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/SpreadSort.java) + * [StalinSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/StalinSort.java) * [StoogeSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/StoogeSort.java) * [StrandSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/StrandSort.java) * [SwapSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/SwapSort.java) @@ -616,6 +623,7 @@ * [CelebrityFinder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/CelebrityFinder.java) * [DecimalToAnyUsingStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/DecimalToAnyUsingStack.java) * [DuplicateBrackets](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/DuplicateBrackets.java) + * [GreatestElementConstantTime](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/GreatestElementConstantTime.java) * [InfixToPostfix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/InfixToPostfix.java) * [InfixToPrefix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/InfixToPrefix.java) * [LargestRectangle](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/LargestRectangle.java) @@ -624,10 +632,12 @@ * [MinStackUsingTwoStacks](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/MinStackUsingTwoStacks.java) * [NextGreaterElement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/NextGreaterElement.java) * [NextSmallerElement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/NextSmallerElement.java) + * [PalindromeWithStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PalindromeWithStack.java) * [PostfixEvaluator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PostfixEvaluator.java) * [PostfixToInfix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PostfixToInfix.java) * [PrefixEvaluator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PrefixEvaluator.java) * [PrefixToInfix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PrefixToInfix.java) + * [SmallestElementConstantTime](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/SmallestElementConstantTime.java) * [SortStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/SortStack.java) * [StackPostfixNotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/StackPostfixNotation.java) * [StackUsingTwoQueues](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/StackUsingTwoQueues.java) @@ -726,12 +736,15 @@ * [AffineCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AffineCipherTest.java) * [AtbashTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AtbashTest.java) * [AutokeyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AutokeyTest.java) + * [BaconianCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BaconianCipherTest.java) * [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java) * [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java) * [ColumnarTranspositionCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/ColumnarTranspositionCipherTest.java) * [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java) + * [DiffieHellmanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DiffieHellmanTest.java) * [ECCTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/ECCTest.java) * [HillCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/HillCipherTest.java) + * [MonoAlphabeticTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/MonoAlphabeticTest.java) * [PlayfairTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PlayfairTest.java) * [PolybiusTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PolybiusTest.java) * [RailFenceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/RailFenceTest.java) @@ -914,6 +927,8 @@ * [BresenhamLineTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/BresenhamLineTest.java) * [ConvexHullTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/ConvexHullTest.java) * [GrahamScanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/GrahamScanTest.java) + * graph + * [StronglyConnectedComponentOptimizedTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/graph/StronglyConnectedComponentOptimizedTest.java) * greedyalgorithms * [ActivitySelectionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/ActivitySelectionTest.java) * [BinaryAdditionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/BinaryAdditionTest.java) @@ -1133,6 +1148,7 @@ * [UnionFindTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UnionFindTest.java) * [UpperBoundTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UpperBoundTest.java) * sorts + * [AdaptiveMergeSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java) * [BeadSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BeadSortTest.java) * [BinaryInsertionSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BinaryInsertionSortTest.java) * [BitonicSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BitonicSortTest.java) @@ -1171,6 +1187,7 @@ * [SortUtilsRandomGeneratorTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/SortUtilsRandomGeneratorTest.java) * [SortUtilsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/SortUtilsTest.java) * [SpreadSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/SpreadSortTest.java) + * [StalinSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/StalinSortTest.java) * [StoogeSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/StoogeSortTest.java) * [StrandSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/StrandSortTest.java) * [SwapSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/SwapSortTest.java) @@ -1184,6 +1201,7 @@ * [CelebrityFinderTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/CelebrityFinderTest.java) * [DecimalToAnyUsingStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/DecimalToAnyUsingStackTest.java) * [DuplicateBracketsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/DuplicateBracketsTest.java) + * [GreatestElementConstantTimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/GreatestElementConstantTimeTest.java) * [InfixToPostfixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/InfixToPostfixTest.java) * [InfixToPrefixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/InfixToPrefixTest.java) * [LargestRectangleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/LargestRectangleTest.java) @@ -1191,10 +1209,12 @@ * [MinStackUsingTwoStacksTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/MinStackUsingTwoStacksTest.java) * [NextGreaterElementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/NextGreaterElementTest.java) * [NextSmallerElementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/NextSmallerElementTest.java) + * [PalindromeWithStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PalindromeWithStackTest.java) * [PostfixEvaluatorTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java) * [PostfixToInfixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PostfixToInfixTest.java) * [PrefixEvaluatorTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PrefixEvaluatorTest.java) * [PrefixToInfixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PrefixToInfixTest.java) + * [SmallestElementConstantTimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/SmallestElementConstantTimeTest.java) * [SortStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/SortStackTest.java) * [StackPostfixNotationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/StackPostfixNotationTest.java) * [StackUsingTwoQueuesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/StackUsingTwoQueuesTest.java) diff --git a/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java b/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java index d3b938bf492d..e85c608af5d0 100644 --- a/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java +++ b/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java @@ -2,7 +2,28 @@ import java.util.Map; +/** + * A utility class to convert integers to their English word representation. + * + *

The class supports conversion of numbers from 0 to 2,147,483,647 + * (the maximum value of a 32-bit signed integer). It divides the number + * into groups of three digits (thousands, millions, billions, etc.) and + * translates each group into words.

+ * + *

Example Usage

+ * 
+ *   IntegerToEnglish.integerToEnglishWords(12345);
+ *   // Output: "Twelve Thousand Three Hundred Forty Five"
+ *
+ * + *

This class uses two maps:

+ * + */ public final class IntegerToEnglish { + private static final Map BASE_NUMBERS_MAP = Map.ofEntries(Map.entry(0, ""), Map.entry(1, "One"), Map.entry(2, "Two"), Map.entry(3, "Three"), Map.entry(4, "Four"), Map.entry(5, "Five"), Map.entry(6, "Six"), Map.entry(7, "Seven"), Map.entry(8, "Eight"), Map.entry(9, "Nine"), Map.entry(10, "Ten"), Map.entry(11, "Eleven"), Map.entry(12, "Twelve"), Map.entry(13, "Thirteen"), Map.entry(14, "Fourteen"), Map.entry(15, "Fifteen"), Map.entry(16, "Sixteen"), Map.entry(17, "Seventeen"), Map.entry(18, "Eighteen"), Map.entry(19, "Nineteen"), Map.entry(20, "Twenty"), Map.entry(30, "Thirty"), Map.entry(40, "Forty"), Map.entry(50, "Fifty"), Map.entry(60, "Sixty"), Map.entry(70, "Seventy"), Map.entry(80, "Eighty"), Map.entry(90, "Ninety"), Map.entry(100, "Hundred")); @@ -13,35 +34,46 @@ private IntegerToEnglish() { } /** - converts numbers < 1000 to english words + * Converts numbers less than 1000 into English words. + * + * @param number the integer value (0-999) to convert + * @return the English word representation of the input number */ private static String convertToWords(int number) { int remainder = number % 100; - - String result; + StringBuilder result = new StringBuilder(); if (remainder <= 20) { - result = BASE_NUMBERS_MAP.get(remainder); + result.append(BASE_NUMBERS_MAP.get(remainder)); } else if (BASE_NUMBERS_MAP.containsKey(remainder)) { - result = BASE_NUMBERS_MAP.get(remainder); + result.append(BASE_NUMBERS_MAP.get(remainder)); } else { int tensDigit = remainder / 10; int onesDigit = remainder % 10; - - result = String.format("%s %s", BASE_NUMBERS_MAP.get(tensDigit * 10), BASE_NUMBERS_MAP.get(onesDigit)); + String tens = BASE_NUMBERS_MAP.getOrDefault(tensDigit * 10, ""); + String ones = BASE_NUMBERS_MAP.getOrDefault(onesDigit, ""); + result.append(tens); + if (ones != null && !ones.isEmpty()) { + result.append(" ").append(ones); + } } int hundredsDigit = number / 100; - if (hundredsDigit > 0) { - result = String.format("%s %s%s", BASE_NUMBERS_MAP.get(hundredsDigit), BASE_NUMBERS_MAP.get(100), result.isEmpty() ? "" : " " + result); + if (result.length() > 0) { + result.insert(0, " "); + } + result.insert(0, String.format("%s Hundred", BASE_NUMBERS_MAP.get(hundredsDigit))); } - return result; + return result.toString().trim(); } /** - Only convert groups of three digit if they are non-zero + * Converts a non-negative integer to its English word representation. + * + * @param number the integer to convert (0-2,147,483,647) + * @return the English word representation of the input number */ public static String integerToEnglishWords(int number) { if (number == 0) { @@ -49,7 +81,6 @@ public static String integerToEnglishWords(int number) { } StringBuilder result = new StringBuilder(); - int index = 0; while (number > 0) { @@ -58,23 +89,20 @@ public static String integerToEnglishWords(int number) { if (remainder > 0) { String subResult = convertToWords(remainder); - if (!subResult.isEmpty()) { - if (!result.isEmpty()) { - result.insert(0, subResult + " " + THOUSAND_POWER_MAP.get(index) + " "); - } else { - if (index > 0) { - result = new StringBuilder(subResult + " " + THOUSAND_POWER_MAP.get(index)); - } else { - result = new StringBuilder(subResult); - } + if (index > 0) { + subResult += " " + THOUSAND_POWER_MAP.get(index); + } + if (result.length() > 0) { + result.insert(0, " "); } + result.insert(0, subResult); } } index++; } - return result.toString(); + return result.toString().trim(); } } diff --git a/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java b/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java index 49c43402aeca..c2a94794b7f8 100644 --- a/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java +++ b/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java @@ -11,5 +11,36 @@ public void testIntegerToEnglish() { assertEquals("Two Billion One Hundred Forty Seven Million Four Hundred Eighty Three Thousand Six Hundred Forty Seven", IntegerToEnglish.integerToEnglishWords(2147483647)); assertEquals("One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven", IntegerToEnglish.integerToEnglishWords(1234567)); assertEquals("Twelve Thousand Three Hundred Forty Five", IntegerToEnglish.integerToEnglishWords(12345)); + assertEquals("One Hundred", IntegerToEnglish.integerToEnglishWords(100)); + assertEquals("Zero", IntegerToEnglish.integerToEnglishWords(0)); + } + + @Test + public void testSmallNumbers() { + assertEquals("Ten", IntegerToEnglish.integerToEnglishWords(10)); + assertEquals("Nineteen", IntegerToEnglish.integerToEnglishWords(19)); + assertEquals("Twenty One", IntegerToEnglish.integerToEnglishWords(21)); + assertEquals("Ninety Nine", IntegerToEnglish.integerToEnglishWords(99)); + } + + @Test + public void testHundreds() { + assertEquals("One Hundred One", IntegerToEnglish.integerToEnglishWords(101)); + assertEquals("Five Hundred Fifty", IntegerToEnglish.integerToEnglishWords(550)); + assertEquals("Nine Hundred Ninety Nine", IntegerToEnglish.integerToEnglishWords(999)); + } + + @Test + public void testThousands() { + assertEquals("One Thousand", IntegerToEnglish.integerToEnglishWords(1000)); + assertEquals("Ten Thousand One", IntegerToEnglish.integerToEnglishWords(10001)); + assertEquals("Seventy Six Thousand Five Hundred Forty Three", IntegerToEnglish.integerToEnglishWords(76543)); + } + + @Test + public void testEdgeCases() { + assertEquals("One Million", IntegerToEnglish.integerToEnglishWords(1_000_000)); + assertEquals("One Billion", IntegerToEnglish.integerToEnglishWords(1_000_000_000)); + assertEquals("Two Thousand", IntegerToEnglish.integerToEnglishWords(2000)); } }