Implement domain entities, parsing input files scratch

Author: LyashenkoGS

src/main/java/com/google/hashcode/App.java

@@ -1,7 +1,22 @@
 package com.google.hashcode;
 
+import com.google.hashcode.entity.Pizza;
+import com.google.hashcode.entity.PizzaCell;
+import com.google.hashcode.utils.IoUtils;
+
+import java.io.File;
+import java.io.IOException;
+
+
 public class App {
-    public static void main(String[] args) {
-        System.out.println("GoogleHashCode2017");
+    public static void main(String[] args) throws IOException {
+        String exampleInputFile = "inputDataSets/example.in";
+        PizzaCell[][] pizzaCells = IoUtils.parsePizza(exampleInputFile);
+        Pizza pizza = new Pizza(new File(exampleInputFile), pizzaCells, IoUtils.parseSliceInstructions(exampleInputFile));
+
+        System.out.println("GoogleHashCode2017! Pizza task");
+        System.out.print(pizza);
+
     }
+
 }

src/main/java/com/google/hashcode/entity/Pizza.java

@@ -0,0 +1,44 @@
+package com.google.hashcode.entity;
+
+import com.google.hashcode.utils.IoUtils;
+
+import java.io.File;
+
+/**
+ * Represents an immutable pizza
+ *
+ * @author Grigoriy Lyashenko (Grog).
+ */
+public class Pizza {
+
+    private final File input;
+    private final PizzaCell[][] pizzaCells;
+    private final SliceInstruction sliceInstruction;
+
+    public Pizza(File input, PizzaCell[][] pizzaCells, SliceInstruction sliceInstruction) {
+        this.input = input;
+        this.pizzaCells = pizzaCells;
+        this.sliceInstruction = sliceInstruction;
+    }
+
+    public File getInput() {
+        return input;
+    }
+
+    public PizzaCell[][] getPizzaCells() {
+        return pizzaCells;
+    }
+
+
+    @Override
+    public String toString() {
+        return input.toString() +
+                "\n" + IoUtils.convertToHumanReadableTable(pizzaCells) +
+                "\n" + sliceInstruction.toString();
+    }
+
+
+    public SliceInstruction getSliceInstruction() {
+        return sliceInstruction;
+    }
+}

src/main/java/com/google/hashcode/entity/PizzaCell.java

@@ -0,0 +1,20 @@
+package com.google.hashcode.entity;
+
+/**
+ * Represents possible pizza cell types
+ *
+ * @author Grigoriy Lyashenko (Grog).
+ */
+public enum PizzaCell {
+    MUSHROOM("M"), TOMATO("T");
+    private final String type;
+
+    PizzaCell(final String type) {
+        this.type = type;
+    }
+
+    @Override
+    public String toString() {
+        return type;
+    }
+}

src/main/java/com/google/hashcode/entity/SliceInstruction.java

@@ -0,0 +1,31 @@
+package com.google.hashcode.entity;
+
+/**
+ * Instructions how to slice a pizza
+ *
+ * @author Grigoriy Lyashenko (Grog).
+ */
+public class SliceInstruction {
+    private final Integer minNumberOfIngredientPerSlice;
+    private final Integer maxNumberOfCellsPerSlice;
+
+    public SliceInstruction(Integer minNumberOfIngredientPerSlice, Integer maxNumberOfIngredientPerSlice) {
+        this.minNumberOfIngredientPerSlice = minNumberOfIngredientPerSlice;
+        this.maxNumberOfCellsPerSlice = maxNumberOfIngredientPerSlice;
+    }
+
+    public Integer getMinNumberOfIngredientPerSlice() {
+        return minNumberOfIngredientPerSlice;
+    }
+
+    public Integer getMaxNumberOfCellsPerSlice() {
+        return maxNumberOfCellsPerSlice;
+    }
+
+    @Override
+    public String toString() {
+        return "SliceInstructions: \n" +
+                "min " + minNumberOfIngredientPerSlice + " ingredient per slice, " +
+                "max " + maxNumberOfCellsPerSlice + " cells per slice ";
+    }
+}

src/main/java/com/google/hashcode/utils/IoUtils.java

@@ -0,0 +1,83 @@
+package com.google.hashcode.utils;
+
+import com.google.hashcode.entity.PizzaCell;
+import com.google.hashcode.entity.SliceInstruction;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+/**
+ * @author Grigoriy Lyashenko (Grog).
+ */
+public class IoUtils {
+
+    /**
+     * Parses given input file to a 2d pizza cells array
+     *
+     * @param file input file
+     * @return 2d array representing a pizza
+     * @throws IOException parsing fail
+     */
+    public static PizzaCell[][] parsePizza(String file) throws IOException {
+        try (FileReader fileReader = new FileReader(file)) {
+            BufferedReader br = new BufferedReader(fileReader);
+            //parse the first line
+            String[] headerTokens = br.readLine().split(" ");
+            int rowsCount = Integer.parseInt(headerTokens[0]);
+            int columnsCount = Integer.parseInt(headerTokens[1]);
+            //declare a pizza cells array
+            PizzaCell[][] pizzaCells = new PizzaCell[rowsCount][columnsCount];
+            int row = 0;
+            String fileLine;
+            while ((fileLine = br.readLine()) != null) {
+                for (int i = 0; i < fileLine.length(); i++) {
+                    Character literal = fileLine.charAt(i);
+                    if (literal.toString().equals(PizzaCell.TOMATO.toString())) {
+                        pizzaCells[row][i] = PizzaCell.TOMATO;
+                    } else if (literal.toString().equals(PizzaCell.MUSHROOM.toString())) {
+                        pizzaCells[row][i] = PizzaCell.MUSHROOM;
+                    }
+                }
+                row++;
+            }
+            return pizzaCells;
+        }
+    }
+
+    /**
+     * Produces SliceInstructions based on given input data set
+     *
+     * @param file input data set
+     * @return slice instructions
+     * @throws IOException file reading error
+     */
+    public static SliceInstruction parseSliceInstructions(String file) throws IOException {
+        try (FileReader fileReader = new FileReader(file)) {
+            BufferedReader br = new BufferedReader(fileReader);
+            String[] headerTokens = br.readLine().split(" ");
+            int minNumberOfIngredientPerSlice = Integer.parseInt(headerTokens[2]);
+            int maxNumberOfCellsPerSlice = Integer.parseInt(headerTokens[3]);
+            return new SliceInstruction(minNumberOfIngredientPerSlice, maxNumberOfCellsPerSlice);
+        }
+    }
+
+
+    /**
+     * Converts given pizza cells 2d array to human readable string representation
+     *
+     * @param pizzaCells given array
+     * @return table like String representation
+     */
+    public static String convertToHumanReadableTable(PizzaCell[][] pizzaCells) {
+        StringBuilder output = new StringBuilder();
+        for (Enum[] row : pizzaCells) {
+            for (Enum cell : row) {
+                output.append(cell).append(" ");
+            }
+            output.append("\n");
+        }
+        return output.toString();
+    }
+
+}

src/test/java/com/google/hashcode/AppTest.java

@@ -2,10 +2,12 @@
 
 import org.junit.Test;
 
+import java.io.IOException;
+
 public class AppTest {
 
     @Test
-    public void main() {
+    public void main() throws IOException {
         App.main(new String[0]);
     }
 

src/test/java/com/google/hashcode/utils/IoUtilsTest.java

@@ -0,0 +1,32 @@
+package com.google.hashcode.utils;
+
+import com.google.hashcode.entity.PizzaCell;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+
+/**
+ * @author Grigoriy Lyashenko (Grog).
+ */
+public class IoUtilsTest {
+    private final String examplePizzaFile = "inputDataSets/example.in";
+
+    @Test
+    public void parseExampleInput() throws IOException {
+        PizzaCell[][] pizzaCells = IoUtils.parsePizza(examplePizzaFile);
+        assertEquals("We expect" + examplePizzaFile + "contains 3 rows", 3, pizzaCells.length);
+        assertEquals("We expect" + examplePizzaFile + "contains 5 columns", 5, pizzaCells[0].length);
+        assertFalse("We expect no null value in pizzaCells", IoUtils.convertToHumanReadableTable(pizzaCells).contains("null"));
+    }
+
+    @Test
+    public void parseExampleSliceInstructions() throws IOException {
+        assertEquals("We expect min 1 ingredient per slice", 1,
+                IoUtils.parseSliceInstructions(examplePizzaFile).getMinNumberOfIngredientPerSlice().intValue());
+        assertEquals("We expect max 6 cells per slice", 6,
+                IoUtils.parseSliceInstructions(examplePizzaFile).getMaxNumberOfCellsPerSlice().intValue());
+    }
+}