Implementation of TreeWriter and TreeParser + UnitTests by Kraynov Maxim

pom.xml

@@ -1,13 +1,23 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.getintent.interview</groupId>
     <artifactId>javatest1</artifactId>
     <version>1.0</version>
     <packaging>jar</packaging>
     <dependencies>
-
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.8.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.1</version>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

src/main/java/com/getintent/interview/TreeNode.java

@@ -11,7 +11,16 @@ public TreeNode(int value) {
         this.value = value;
     }
 
-    public void addChild(TreeNode child) {
+    public int getValue() {
+        return value;
+    }
+
+    public List<TreeNode> getChildren() {
+        return children;
+    }
+
+    public TreeNode addChild(TreeNode child) {
         children.add(child);
+        return this;
     }
 }

src/main/java/com/getintent/interview/TreeParser.java

@@ -0,0 +1,39 @@
+package com.getintent.interview;
+
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * Created by Kraynov M. on 11/12/13.
+ */
+public class TreeParser {
+    int lastLine = 1;
+
+    private static TreeNode parseLine(String line) {
+        return new TreeNode(Integer.parseInt(line));
+    }
+
+    public TreeNode parse(String s) {
+        String[] lines = s.split("\\r?\\n");
+        String firstLine = lines[0];
+        TreeNode root = parseLine(firstLine);
+        parse(root, 0, lines);
+        return root;
+    }
+
+    private void parse(TreeNode parent, int depth, String[] lines) {
+        for (; lastLine < lines.length; ) {
+            String nextLine = lines[lastLine];
+            int spaceNumber = StringUtils.countMatches(nextLine, " ");
+            if (spaceNumber < depth) {
+                break;
+            }
+            String value = nextLine.trim();
+            TreeNode node = parseLine(value);
+            lastLine++;
+            if (parent != null) {
+                parent.addChild(node);
+            }
+            parse(node, spaceNumber + 1, lines);
+        }
+    }
+}

src/main/java/com/getintent/interview/TreePrinter.java

@@ -0,0 +1,30 @@
+package com.getintent.interview;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.util.Iterator;
+
+/**
+ * Created by Kraynov M. on 11/12/13.
+ */
+public class TreePrinter implements TreeWriter {
+
+    private static void write(TreeNode node, String spaceNumber, Writer w) throws IOException {
+        if (node == null) {
+            return;
+        }
+        w.append(spaceNumber + node.getValue() + "\n");
+        for (Iterator<TreeNode> iter = node.getChildren().iterator(); iter.hasNext(); ) {
+            write(iter.next(), spaceNumber + " ", w);
+        }
+    }
+
+    @Override
+    public void write(TreeNode node, Writer w) {
+        try {
+            write(node, "", w);
+        } catch (IOException e) {
+            System.out.println("Error was occurred while writing tree" + e.getMessage());
+        }
+    }
+}

src/test/java/TestTreeParserAndWriter.java

@@ -0,0 +1,55 @@
+import com.getintent.interview.TreeNode;
+import com.getintent.interview.TreeParser;
+import com.getintent.interview.TreePrinter;
+import junit.framework.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.io.StringWriter;
+import java.util.Arrays;
+import java.util.Collection;
+
+/**
+ * Created by Kraynov M. on 11/12/13.
+ */
+@RunWith(value = Parameterized.class)
+public class TestTreeParserAndWriter {
+    private static String tree1 = "6\n" +
+            " 7\n" +
+            "  3\n" +
+            "   4\n" +
+            " 10\n" +
+            " 13\n" +
+            "  16\n" +
+            "  21\n";
+    private static String tree2 = "6\n" +
+            " 7\n" +
+            " 8\n";
+    private static String tree3 = "6\n" +
+            " 7\n" +
+            " 8\n" +
+            "  9\n" +
+            " 10\n";
+    private String treeString;
+
+    public TestTreeParserAndWriter(String treeString) {
+        this.treeString = treeString;
+    }
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        Object[][] data = new Object[][]{{tree1}, {tree2}, {tree3}};
+        return Arrays.asList(data);
+    }
+
+    @Test
+    public void testParseAndWrite() {
+        TreeParser parser = new TreeParser();
+        TreeNode parsedTree = parser.parse(treeString);
+        TreePrinter printer = new TreePrinter();
+        StringWriter writer = new StringWriter();
+        printer.write(parsedTree, writer);
+        Assert.assertEquals("Parser or Writer is not correct!", treeString, writer.toString());
+    }
+}

src/test/java/TestTreePrinter.java

@@ -0,0 +1,37 @@
+import com.getintent.interview.TreeNode;
+import com.getintent.interview.TreePrinter;
+import junit.framework.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.StringWriter;
+
+/**
+ * Created by Kraynov M. on 11/12/13.
+ */
+public class TestTreePrinter {
+    private static String tree1 = "6\n" +
+            " 7\n" +
+            "  3\n" +
+            "   4\n" +
+            " 10\n" +
+            " 13\n" +
+            "  16\n" +
+            "  21\n";
+    private TreeNode treeNode1;
+
+    @Before
+    public void init() {
+        treeNode1 = new TreeNode(6).addChild(new TreeNode(7).addChild(new TreeNode(3).addChild(new TreeNode(4))))
+                .addChild(new TreeNode(10))
+                .addChild(new TreeNode(13).addChild(new TreeNode(16)).addChild(new TreeNode(21)));
+    }
+
+    @Test
+    public void testWrite() {
+        TreePrinter printer = new TreePrinter();
+        StringWriter writer = new StringWriter();
+        printer.write(treeNode1, writer);
+        Assert.assertEquals("Writer is not correct!", tree1, writer.toString());
+    }
+}