From 0a0c30a60ae888faeea352c9844d86093594c06f Mon Sep 17 00:00:00 2001
From: Volkov Denis <volkov.denis.dev@yandex.ru>
Date: Tue, 21 Apr 2020 18:34:27 +0500
Subject: [PATCH] solve homework 4

---
 .../homework_4/src/main/scala/Cell.scala      | 26 +++++++++++++++++++
 .../homework_4/src/main/scala/Table.scala     | 19 ++++++++++++++
 .../homework_4/src/test/scala/Test.scala      |  2 +-
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/homeworks/homework_4/src/main/scala/Cell.scala b/homeworks/homework_4/src/main/scala/Cell.scala
index e69de29..9bb7279 100644
--- a/homeworks/homework_4/src/main/scala/Cell.scala
+++ b/homeworks/homework_4/src/main/scala/Cell.scala
@@ -0,0 +1,26 @@
+trait Cell
+
+case class EmptyCell() extends Cell {
+    override def toString: String = "empty"
+}
+
+case class NumberCell(number: Int) extends Cell
+{
+    override def toString: String = number.toString
+}
+
+case class StringCell(text: String) extends Cell
+{
+    override def toString: String = text
+}
+
+case class ReferenceCell(x: Int, y: Int, table: Table) extends Cell {
+  override def toString: String = {
+    table.getCell(x, y) match {
+      case Some(ref: ReferenceCell) => 
+        if (ref.table.getCell(ref.x, ref.y).get == this) "cyclic" else ref.toString
+      case other => table.getCell(x, y).get.toString
+    }
+  }
+} 
+
diff --git a/homeworks/homework_4/src/main/scala/Table.scala b/homeworks/homework_4/src/main/scala/Table.scala
index e69de29..caec246 100644
--- a/homeworks/homework_4/src/main/scala/Table.scala
+++ b/homeworks/homework_4/src/main/scala/Table.scala
@@ -0,0 +1,19 @@
+import scala.collection.mutable
+
+class Table(var width: Int, var height: Int) {
+    private val table = mutable.HashMap[(Int, Int), Cell]()
+
+    def getCell(x: Int, y: Int): Option[Cell] = {
+      if(inRange(x, y))
+        table get((x, y)) orElse Some(new EmptyCell)
+      else
+        Option.empty[Cell]
+    }
+
+    def setCell(x: Int, y: Int, cell: Cell): Unit = {
+        table((x, y)) = cell
+    }
+
+    def inRange(x: Int, y: Int): Boolean =
+        x >= 0 && y >= 0 && x <= width && y <= height
+}
\ No newline at end of file
diff --git a/homeworks/homework_4/src/test/scala/Test.scala b/homeworks/homework_4/src/test/scala/Test.scala
index 08a0ff6..1335775 100644
--- a/homeworks/homework_4/src/test/scala/Test.scala
+++ b/homeworks/homework_4/src/test/scala/Test.scala
@@ -5,7 +5,7 @@ object Test extends TestSuite {
         'test_createTable - {
             val table = new Table(3, 3)
             for (i <- 0 until 9) {
-                assert(table.getCell(i / 3, i % 3).toString == Some("empty"))
+                assert(table.getCell(i / 3, i % 3).map(_.toString) == Some("empty"))
             }
             assert(table.getCell(0, -1).map(_.toString) == None)
             assert(table.getCell(-1, 0).map(_.toString) == None)