Merge pull request #1283 from jssander/fix-palindrome-products

update palindrome-products

exercises/palindrome-products/.meta/src/reference/java/PalindromeCalculator.java

@@ -3,6 +3,10 @@ import java.util.*;
 public class PalindromeCalculator {
 
     public SortedMap<Long, List<List<Integer>>> getPalindromeProductsWithFactors(int minFactor, int maxFactor) {
+    	if(minFactor > maxFactor) {
+    		throw new IllegalArgumentException("invalid input: min is " + minFactor + " and max is " + maxFactor);
+    	}
+    	
         SortedMap<Long, List<List<Integer>>> palindromeSortedList = new TreeMap<>();
         long num;
         List<List<Integer>> factors;
@@ -19,6 +23,11 @@ public class PalindromeCalculator {
                 }
             }
         }
+        
+        if(palindromeSortedList.size() == 0) {
+    		throw new NoSuchElementException("no palindrome with factors in the range " + minFactor + " to " + maxFactor);
+    	}
+        
         return Collections.unmodifiableSortedMap(palindromeSortedList);
     }
 

exercises/palindrome-products/.meta/version

@@ -0,0 +1 @@
+1.1.0

exercises/palindrome-products/src/test/java/PalindromeCalculatorTest.java

@@ -1,12 +1,17 @@
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
 
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.SortedMap;
 import java.util.stream.Collectors;
+import java.util.NoSuchElementException;
+
+import java.lang.IllegalArgumentException;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -14,23 +19,41 @@ import static org.junit.Assert.assertNotNull;
 
 public class PalindromeCalculatorTest {
     private PalindromeCalculator palindromeCalculator;
+    
+    @Rule
+    public ExpectedException expectedException = ExpectedException.none();
 
     @Before
     public void setup() {
         palindromeCalculator = new PalindromeCalculator();
     }
+    
+    @Test
+    public void smallestPalindromeFromSingleDigitFactors() {
+        List<List<Integer>> expected = Collections.unmodifiableList(
+                Arrays.asList(
+                        Arrays.asList(1, 1)
+                )
+        );
+        long expectedValue = 1l;
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1, 9);
 
+        checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.firstKey());
+    }
+
+    @Ignore("Remove to run test")
     @Test
     public void largestPalindromeFromSingleDigitFactors() {
-        final List<List<Integer>> expected = Collections.unmodifiableList(
+        List<List<Integer>> expected = Collections.unmodifiableList(
                 Arrays.asList(
                         Arrays.asList(1, 9),
                         Arrays.asList(3, 3)
                 )
         );
-        final long expectedValue = 9l;
+        long expectedValue = 9l;
 
-        final SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1, 9);
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1, 9);
 
         checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.lastKey());
     }
@@ -38,14 +61,14 @@ public class PalindromeCalculatorTest {
     @Ignore("Remove to run test")
     @Test
     public void largestPalindromeFromDoubleDigitFactors() {
-        final List<List<Integer>> expected = Collections.unmodifiableList(
+        List<List<Integer>> expected = Collections.unmodifiableList(
                 Arrays.asList(
                         Arrays.asList(91, 99)
                 )
         );
-        final long expectedValue = 9009l;
+        long expectedValue = 9009l;
 
-        final SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(10, 99);
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(10, 99);
 
         checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.lastKey());
     }
@@ -53,14 +76,14 @@ public class PalindromeCalculatorTest {
     @Ignore("Remove to run test")
     @Test
     public void smallestPalindromeFromDoubleDigitFactors() {
-        final List<List<Integer>> expected = Collections.unmodifiableList(
+        List<List<Integer>> expected = Collections.unmodifiableList(
                 Arrays.asList(
                         Arrays.asList(11, 11)
                 )
         );
-        final long expectedValue = 121l;
+        long expectedValue = 121l;
 
-        final SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(10, 99);
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(10, 99);
 
         checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.firstKey());
     }
@@ -68,14 +91,14 @@ public class PalindromeCalculatorTest {
     @Ignore("Remove to run test")
     @Test
     public void largestPalindromeFromTripleDigitFactors() {
-        final List<List<Integer>> expected = Collections.unmodifiableList(
+        List<List<Integer>> expected = Collections.unmodifiableList(
                 Arrays.asList(
                         Arrays.asList(913, 993)
                 )
         );
-        final long expectedValue = 906609l;
+        long expectedValue = 906609l;
 
-        final SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(100, 999);
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(100, 999);
 
         checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.lastKey());
     }
@@ -83,17 +106,89 @@ public class PalindromeCalculatorTest {
     @Ignore("Remove to run test")
     @Test
     public void smallestPalindromeFromTripleDigitFactors() {
-        final List<List<Integer>> expected = Collections.unmodifiableList(
+        List<List<Integer>> expected = Collections.unmodifiableList(
                 Arrays.asList(
                         Arrays.asList(101, 101)
                 )
         );
-        final long expectedValue = 10201l;
+        long expectedValue = 10201l;
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(100, 999);
+
+        checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.firstKey());
+    }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void smallestPalindromeFromQuadDigitFactors() {
+        List<List<Integer>> expected = Collections.unmodifiableList(
+                Arrays.asList(
+                        Arrays.asList(1001, 1001)
+                )
+        );
+        long expectedValue = 1002001l;
 
-        final SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(100, 999);
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1000, 9999);
 
         checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.firstKey());
     }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void largestPalindromeFromQuadDigitFactors() {
+        List<List<Integer>> expected = Collections.unmodifiableList(
+                Arrays.asList(
+                        Arrays.asList(9901, 9999)
+                )
+        );
+        long expectedValue = 99000099l;
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1000, 9999);
+
+        checkPalindromeWithFactorsMatchesExpected(expected, expectedValue, palindromes, palindromes.lastKey());
+    }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void emtpyResultSmallestNoPalindromeInRange() {
+        
+        expectedException.expect(NoSuchElementException.class);
+        expectedException.expectMessage("no palindrome with factors in the range 1002 to 1003");
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(1002, 1003);
+    }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void emtpyResultLargestNoPalindromeInRange() {
+        
+        expectedException.expect(NoSuchElementException.class);
+        expectedException.expectMessage("no palindrome with factors in the range 15 to 15");
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(15, 15);
+    }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void errorSmallestMinIsMoreThanMax() {
+        
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("invalid input: min is 10000 and max is 1");
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(10000, 1);
+    }
+    
+    @Ignore("Remove to run test")
+    @Test
+    public void errorLargestMinIsMoreThanMax() {
+        
+        expectedException.expect(IllegalArgumentException.class);
+        expectedException.expectMessage("invalid input: min is 2 and max is 1");
+
+        SortedMap<Long, List<List<Integer>>> palindromes = palindromeCalculator.getPalindromeProductsWithFactors(2, 1);
+    }
+    
+    
 
     private void checkPalindromeWithFactorsMatchesExpected(List<List<Integer>> expectedPalindromeFactors,
                                                            long expectedValueOfPalindrome,