Merge pull request #627 from exercism/saddle-pts-cleanup

saddle-points: API cleanup, ordering

config.json

       "topics": []
     },
     {
+      "slug": "saddle-points",
+      "difficulty": 4,
+      "topics": []
+    },
+    {
       "slug": "diamond",
       "difficulty": 4,
       "topics": []
       "topics": []
     },
     {
-      "slug": "saddle-points",
-      "difficulty": 1,
-      "topics": []
-    },
-    {
       "slug": "run-length-encoding",
       "difficulty": 1,
       "topics": []

exercises/saddle-points/src/example/java/Matrix.java

-import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 final class Matrix {
 
     this.values = values;
   }
 
-  List<MatrixCoordinate> getSaddlePoints() {
-    final List<MatrixCoordinate> result = new ArrayList<>();
+  Set<MatrixCoordinate> getSaddlePoints() {
+    final Set<MatrixCoordinate> result = new HashSet<>();
 
     if (values.isEmpty()) {
       return result;
     return values.stream()
         .map(row -> row.get(column))
         .min(Integer::compareTo)
-        .get();
+        .orElseThrow(() -> new IllegalArgumentException("Column cannot be empty"));
   }
 
 }

exercises/saddle-points/src/example/java/MatrixCoordinate.java

 
   private final int row;
 
-  private final int column;
+  private final int col;
 
-  MatrixCoordinate(final int row, final int column) {
+  MatrixCoordinate(final int row, final int col) {
     this.row = row;
-    this.column = column;
+    this.col = col;
   }
 
   // Generated equals and hashcode.
 
     final MatrixCoordinate that = (MatrixCoordinate) o;
 
-    return row == that.row && column == that.column;
+    return row == that.row && col == that.col;
   }
 
   @Override
   public int hashCode() {
     int result = row;
-    result = 31 * result + column;
+    result = 31 * result + col;
     return result;
   }
 

exercises/saddle-points/src/main/java/MatrixCoordinate.java

 
   private final int row;
 
-  private final int column;
+  private final int col;
 
-  MatrixCoordinate(final int row, final int column) {
+  MatrixCoordinate(final int row, final int col) {
     this.row = row;
-    this.column = column;
+    this.col = col;
   }
 
   // Generated equals and hashcode.
 
     final MatrixCoordinate that = (MatrixCoordinate) o;
 
-    return row == that.row && column == that.column;
+    return row == that.row && col == that.col;
   }
 
   @Override
   public int hashCode() {
     int result = row;
-    result = 31 * result + column;
+    result = 31 * result + col;
     return result;
   }
 

exercises/saddle-points/src/test/java/MatrixTest.java

 import org.junit.Ignore;
 import org.junit.Test;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 import static org.junit.Assert.assertEquals;
 
+/*
+ * version: 1.0.0
+ */
 public class MatrixTest {
 
     @Test
             Arrays.asList(6, 6, 7)
         ));
 
-        List<MatrixCoordinate> expectedSaddlePoints = Collections.singletonList(new MatrixCoordinate(1, 0));
+        Set<MatrixCoordinate> expectedSaddlePoints = Collections.singleton(new MatrixCoordinate(1, 0));
 
         assertEquals(expectedSaddlePoints, matrix.getSaddlePoints());
     }
     public void testCanIdentifyThatEmptyMatrixHasNoSaddlePoints() {
         Matrix matrix = new Matrix(new ArrayList<>());
 
-        List<MatrixCoordinate> expectedSaddlePoints = new ArrayList<>();
+        Set<MatrixCoordinate> expectedSaddlePoints = Collections.emptySet();
 
         assertEquals(expectedSaddlePoints, matrix.getSaddlePoints());
     }
             Arrays.asList(2, 3, 1)
         ));
 
-        List<MatrixCoordinate> expectedSaddlePoints = new ArrayList<>();
+        Set<MatrixCoordinate> expectedSaddlePoints = Collections.emptySet();
 
         assertEquals(expectedSaddlePoints, matrix.getSaddlePoints());
     }
             Arrays.asList(1, 5, 4)
         ));
 
-        List<MatrixCoordinate> expectedSaddlePoints = Arrays.asList(
+        Set<MatrixCoordinate> expectedSaddlePoints = new HashSet<>(Arrays.asList(
             new MatrixCoordinate(0, 1),
             new MatrixCoordinate(1, 1),
             new MatrixCoordinate(2, 1)
-        );
+        ));
 
         assertEquals(expectedSaddlePoints, matrix.getSaddlePoints());
     }
             Arrays.asList(3, 2, 5)
         ));
 
-        List<MatrixCoordinate> expectedSaddlePoints = Collections.singletonList(new MatrixCoordinate(2, 2));
+        Set<MatrixCoordinate> expectedSaddlePoints = Collections.singleton(new MatrixCoordinate(2, 2));
 
         assertEquals(expectedSaddlePoints, matrix.getSaddlePoints());
     }