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stkentstkent
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largest-series-product: add to track
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6 files changed

+300
-1
lines changed

‎config.json

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@@ -43,7 +43,8 @@
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"nth-prime",
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"pascals-triangle",
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"beer-song",
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"difference-of-squares"
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"difference-of-squares",
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"largest-series-product"
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],
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"exercises": [
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{
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"slug": "difference-of-squares",
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"difficulty": 1,
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"topics": []
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},
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{
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"slug": "largest-series-product",
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"difficulty": 1,
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"topics": []
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}
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],
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"deprecated": [

‎exercises/largest-series-product/build.gradle

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apply plugin: "java"
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apply plugin: "eclipse"
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apply plugin: "idea"
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repositories {
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mavenCentral()
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}
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dependencies {
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testCompile "junit:junit:4.12"
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}
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test {
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testLogging {
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exceptionFormat = 'full'
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events = ["passed", "failed", "skipped"]
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}
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}

‎exercises/largest-series-product/src/example/java/LargestSeriesProductCalculator.java

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public final class LargestSeriesProductCalculator {
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private final String stringToSearch;
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public LargestSeriesProductCalculator(final String stringToSearch) throws IllegalArgumentException {
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this.stringToSearch = stringToSearch;
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validateStringToSearch();
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}
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public long calculateLargestProductForSeriesLength(final int seriesLength) throws IllegalArgumentException {
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if (seriesLength < 0) {
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throw new IllegalArgumentException("Series length must be non-negative.");
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} else if (seriesLength == 0) {
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return 1;
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} else if (seriesLength > stringToSearch.length()) {
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throw new IllegalArgumentException(
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"Series length must be less than or equal to the length of the string to search.");
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} else {
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long result = 0;
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int numberOfSeriesToCheck = stringToSearch.length() - seriesLength + 1;
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for (int startIndex = 0; startIndex < numberOfSeriesToCheck; startIndex++) {
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/*
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* Note: computing the product of each series fresh each time is not the most efficient solution, but
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* it's the simplest to reason about.
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*/
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result = Math.max(result, computeProductOfSeries(startIndex, seriesLength));
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}
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return result;
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}
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}
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private void validateStringToSearch() throws IllegalArgumentException {
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if (stringToSearch == null) {
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throw new IllegalArgumentException("String to search must be non-null.");
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} else if (!stringToSearch.chars().allMatch(Character::isDigit)) {
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throw new IllegalArgumentException("String to search may only contains digits.");
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}
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}
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private long computeProductOfSeries(final int startIndex, final int seriesLength) {
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// The multiplicative identity is 1.
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long result = 1;
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final int endIndex = startIndex + seriesLength - 1;
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for (int characterIndex = startIndex; characterIndex <= endIndex; characterIndex++) {
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result = result * Character.getNumericValue(stringToSearch.charAt(characterIndex));
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}
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return result;
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}
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}

‎exercises/largest-series-product/src/main/java/LargestSeriesProductCalculator.java

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public class LargestSeriesProductCalculator {
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}

‎exercises/largest-series-product/src/test/java/LargestSeriesProductCalculatorTest.java

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import org.junit.Ignore;
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import org.junit.Rule;
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import org.junit.Test;
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import org.junit.rules.ExpectedException;
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import static org.junit.Assert.assertEquals;
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public final class LargestSeriesProductCalculatorTest {
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@Rule
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public ExpectedException expectedException = ExpectedException.none();
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@Test
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public void testCorrectlyCalculatesLargestProductOfLengthTwoWithNumbersInOrder() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("0123456789");
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final long expectedProduct = 72;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(2);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLengthTwoWithNumbersNotInOrder() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("576802143");
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final long expectedProduct = 48;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(2);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductWhenSeriesLengthEqualsStringToSearchLength() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("29");
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final long expectedProduct = 18;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(2);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLengthThreeWithNumbersInOrder() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("0123456789");
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final long expectedProduct = 504;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(3);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLengthThreeWithNumbersNotInOrder() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("1027839564");
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final long expectedProduct = 270;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(3);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLengthFiveWithNumbersInOrder() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("0123456789");
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final long expectedProduct = 15120;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(5);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductInLongStringToSearchV1() {
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final LargestSeriesProductCalculator calculator
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= new LargestSeriesProductCalculator("73167176531330624919225119674426574742355349194934");
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final long expectedProduct = 23520;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(6);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductInLongStringToSearchV2() {
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final LargestSeriesProductCalculator calculator
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= new LargestSeriesProductCalculator("52677741234314237566414902593461595376319419139427");
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final long expectedProduct = 28350;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(6);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductInLongStringToSearchFromProjectEuler() {
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final LargestSeriesProductCalculator calculator
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= new LargestSeriesProductCalculator("7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450");
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final long expectedProduct = 23514624000L;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(13);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfZeroIfAllDigitsAreZeroes() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("0000");
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final long expectedProduct = 0;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(2);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfZeroIfAllSeriesOfGivenLengthContainZero() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("99099");
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final long expectedProduct = 0;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(3);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testSeriesLengthLongerThanLengthOfStringToTestIsRejected() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("123");
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expectedException.expect(IllegalArgumentException.class);
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expectedException.expectMessage(
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"Series length must be less than or equal to the length of the string to search.");
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calculator.calculateLargestProductForSeriesLength(4);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLength0ForEmptyStringToSearch() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("");
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final long expectedProduct = 1;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(0);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testCorrectlyCalculatesLargestProductOfLength0ForNonEmptyStringToSearch() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("123");
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final long expectedProduct = 1;
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final long actualProduct = calculator.calculateLargestProductForSeriesLength(0);
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assertEquals(expectedProduct, actualProduct);
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}
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@Ignore
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@Test
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public void testEmptyStringToSearchAndSeriesOfNonZeroLengthIsRejected() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("");
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expectedException.expect(IllegalArgumentException.class);
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expectedException.expectMessage(
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"Series length must be less than or equal to the length of the string to search.");
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calculator.calculateLargestProductForSeriesLength(1);
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}
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@Ignore
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@Test
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public void testStringToSearchContainingNonDigitCharacterIsRejected() {
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expectedException.expect(IllegalArgumentException.class);
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expectedException.expectMessage("String to search may only contains digits.");
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new LargestSeriesProductCalculator("1234a5");
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}
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@Ignore
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@Test
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public void testNegativeSeriesLengthIsRejected() {
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final LargestSeriesProductCalculator calculator = new LargestSeriesProductCalculator("12345");
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expectedException.expect(IllegalArgumentException.class);
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expectedException.expectMessage("Series length must be non-negative.");
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calculator.calculateLargestProductForSeriesLength(-1);
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}
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@Ignore
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@Test
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public void testNullStringToSearchIsRejected() {
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expectedException.expect(IllegalArgumentException.class);
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expectedException.expectMessage("String to search must be non-null.");
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new LargestSeriesProductCalculator(null);
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}
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}

‎exercises/settings.gradle

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include 'hamming'
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include 'hexadecimal'
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include 'hello-world'
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include 'largest-series-product'
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include 'linked-list'
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include 'luhn'
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include 'meetup'

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