Implemented matrix exercise.

config.json

@@ -55,7 +55,8 @@
     "wordy",
     "palindrome-products",
     "twelve-days",
-    "sublist"
+    "sublist",
+    "matrix"
   ],
   "exercises": [
     {
@@ -317,6 +318,11 @@
       "slug": "sublist",
       "difficulty": 1,
       "topics": []
+    },
+    {
+      "slug": "matrix",
+      "difficulty": 1,
+      "topics": []
     }
   ],
   "deprecated": [

exercises/matrix/build.gradle

@@ -0,0 +1,17 @@
+apply plugin: "java"
+apply plugin: "eclipse"
+apply plugin: "idea"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testCompile "junit:junit:4.12"
+}
+test {
+    testLogging {
+        exceptionFormat = 'full'
+        events = ["passed", "failed", "skipped"]
+    }
+}

exercises/matrix/src/example/java/Matrix.java

@@ -0,0 +1,35 @@
+public class Matrix {
+    private int[][] matrix;
+
+    public Matrix(String matrixAsString) {
+        String[] rows = matrixAsString.split("\\n");
+        matrix = new int[rows.length][];
+        for (int i = 0; i < rows.length; i++) {
+            String[] columnValues = rows[i].split(" ");
+            matrix[i] = new int[columnValues.length];
+            for (int j = 0; j < columnValues.length; j++) {
+                matrix[i][j] = Integer.valueOf(columnValues[j]);
+            }
+        }
+    }
+
+    public int[] getRow(int rowNumber) {
+        return matrix[rowNumber];
+    }
+
+    public int[] getColumn(int columnNumber) {
+        int[] column = new int[matrix.length];
+        for(int i = 0; i < matrix.length; i++) {
+            column[i] = matrix[i][columnNumber];
+        }
+        return column;
+    }
+
+    public int getRowsCount() {
+        return matrix.length;
+    }
+
+    public int getColumnsCount() {
+        return matrix[0].length;
+    }
+}

exercises/matrix/src/test/java/MatrixTest.java

@@ -0,0 +1,184 @@
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.experimental.runners.Enclosed;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+@RunWith(Enclosed.class)
+public class MatrixTest {
+
+    @RunWith(Parameterized.class)
+    public static class GetFirstRowTest {
+        private Matrix matrix;
+        private int[] firstRow;
+
+        @Parameterized.Parameters(name = "{index}: checking first row of matrix constructed with string \"{0}\".")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", new int[] {0}},
+                    {"0 1", new int[] {0, 1}},
+                    {"0\\n1", new int[] {0}},
+                    {"0 1\\n2 3", new int[] {0, 1}},
+                    {"0 1 2\\n3 4 5\\n6 7 8", new int[] {0, 1, 2}}
+            });
+        }
+
+        public GetFirstRowTest(String matrixAsString, int[] firstRow) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.firstRow = firstRow;
+        }
+
+        @Test
+        public void getFirstRowTest() {
+            assertArrayEquals(matrix.getRow(0), firstRow);
+        }
+    }
+
+    @RunWith(Parameterized.class)
+    public static class GetLastRowTest {
+        private Matrix matrix;
+        private int[] lastRow;
+
+        @Parameterized.Parameters(name = "{index}: checking last row of matrix constructed with string \"{0}\".")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", new int[] {0}},
+                    {"0 1", new int[] {0, 1}},
+                    {"0\\n1", new int[] {1}},
+                    {"0 1\\n2 3", new int[] {2, 3}},
+                    {"0 1 2\\n3 4 5\\n6 7 8", new int[] {6, 7, 8}}
+            });
+        }
+
+        public GetLastRowTest(String matrixAsString, int[] lastRow) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.lastRow = lastRow;
+        }
+
+        @Ignore
+        @Test
+        public void getLastRowTest() {
+            assertArrayEquals(matrix.getRow(matrix.getRowsCount() - 1), lastRow);
+        }
+    }
+
+    @RunWith(Parameterized.class)
+    public static class GetFirstColumnTest {
+        private Matrix matrix;
+        private int[] firstColumn;
+
+        @Parameterized.Parameters(name = "{index}: checking first column of matrix constructed with string \"{0}\".")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", new int[] {0}},
+                    {"0 1", new int[] {0}},
+                    {"0\\n1", new int[] {0, 1}},
+                    {"0 1\\n2 3", new int[] {0, 2}},
+                    {"0 1 2\\n3 4 5\\n6 7 8", new int[] {0, 3, 6}}
+            });
+        }
+
+        public GetFirstColumnTest(String matrixAsString, int[] firstColumn) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.firstColumn = firstColumn;
+        }
+
+        @Ignore
+        @Test
+        public void getFirstColumnTest() {
+            assertArrayEquals(matrix.getColumn(0), firstColumn);
+        }
+    }
+
+
+    @RunWith(Parameterized.class)
+    public static class GetLastColumnTest {
+        private Matrix matrix;
+        private int[] lastColumn;
+
+        @Parameterized.Parameters(name = "{index}: checking last column of matrix constructed with string \"{0}\".")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", new int[] {0}},
+                    {"0 1", new int[] {1}},
+                    {"0\\n1", new int[] {0, 1}},
+                    {"0 1\\n2 3", new int[] {1, 3}},
+                    {"0 1 2\\n3 4 5\\n6 7 8", new int[] {2, 5, 8}}
+            });
+        }
+
+        public GetLastColumnTest(String matrixAsString, int[] lastColumn) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.lastColumn = lastColumn;
+        }
+
+        @Ignore
+        @Test
+        public void getLastColumnTest() {
+            assertArrayEquals(matrix.getColumn(matrix.getColumnsCount() - 1), lastColumn);
+        }
+    }
+
+    @RunWith(Parameterized.class)
+    public static class CountColumnsTest {
+        private Matrix matrix;
+        private int numberOfColumns;
+
+        @Parameterized.Parameters(name = "{index}: expected matrix constructed with string \"{0}\" to have {1} column(s).")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", 1},
+                    {"0 1", 2},
+                    {"0\\n1", 1},
+                    {"0 1\\n2 3", 2},
+                    {"0 1 2\\n3 4 5\\n6 7 8", 3}
+            });
+        }
+
+        public CountColumnsTest(String matrixAsString, int numberOfColumns) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.numberOfColumns = numberOfColumns;
+        }
+
+        @Ignore
+        @Test
+        public void countColumnsTest() {
+            assertEquals(matrix.getColumnsCount(), numberOfColumns);
+        }
+    }
+
+    @RunWith(Parameterized.class)
+    public static class CountRowsTest {
+        private Matrix matrix;
+        private int numberOfRows;
+
+        @Parameterized.Parameters(name = "{index}: expected matrix constructed with string \"{0}\" to have {1} row(s).")
+        public static Collection<Object[]> data() {
+            return Arrays.asList(new Object[][]{
+                    {"0", 1},
+                    {"0 1", 1},
+                    {"0\\n1", 2},
+                    {"0 1\\n2 3", 2},
+                    {"0 1 2\\n3 4 5\\n6 7 8", 3}
+            });
+        }
+
+        public CountRowsTest(String matrixAsString, int numberOfRows) {
+            this.matrix = new Matrix(matrixAsString.replaceAll("\\\\n", "\n"));
+            this.numberOfRows = numberOfRows;
+        }
+
+        @Ignore
+        @Test
+        public void countRowsTest() {
+            assertEquals(matrix.getRowsCount(), numberOfRows);
+        }
+    }
+    
+}

exercises/settings.gradle

@@ -53,4 +53,4 @@ include 'trinary'
 include 'word-count'
 include 'wordy'
 include 'twelve-days'
-
+include 'matrix'