PaulResults.md

PaulResults.md

@@ -0,0 +1,16 @@
+***
+Simulation of 2 dice tossed for 1000000 times.
+***
+
+  2:    27588: 0.03 **
+  3:    55346: 0.06 *****
+  4:    83377: 0.08 ********
+  5:   110439: 0.11 ***********
+  6:   139244: 0.14 *************
+  7:   167051: 0.17 ****************
+  8:   139601: 0.14 *************
+  9:   111389: 0.11 ***********
+ 10:    82921: 0.08 ********
+ 11:    55351: 0.06 *****
+ 12:    27693: 0.03 **
+

pom.xml

@@ -7,6 +7,18 @@
     <groupId>com.zipcodewilmington</groupId>
     <artifactId>Dicey-Lab</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+    </properties>
 
 
 </project>

src/main/java/Bins.java

@@ -1,4 +1,20 @@
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public class Bins {
+    Map<Integer,Integer> binmap;
+    public Bins(int min , int max){
+        this.binmap = Stream
+                .iterate(min,q -> q + 1)
+                .limit(max)
+                .collect(Collectors.toMap( q -> q, q-> 0));
+    }
+    public Integer getBin(int bin){
+        return this.binmap.get(bin);
+    }
+    public void increment(int bin){
+        this.binmap.replace(bin,this.binmap.get(bin)+1);
+    }
 
 }

src/main/java/Dice.java

@@ -1,4 +1,33 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
 public class Dice {
+    private static class Die{
+        private int result;
+        private Die(){
+            this.result =(int) (Math.random()*(6 - 1 + 1) + 1);
+        }
+        private int roll(){
+            return (this.result = (int) (Math.random()*(6 - 1 + 1) + 1));
+        }
+    }
+    private final List<Die> dice;
+    public Dice(int numberOfDice){
+        dice = Stream
+                .generate(Die::new)
+                .limit(numberOfDice)
+                .collect(Collectors.toList());
+    }
+    public int tossAndSum(){
+        return dice.stream()
+                .mapToInt(Die::roll)
+                .sum();
+    }
+    public List<Die> getDice(){
+        return dice;
+    }
 
 
 }

src/main/java/Simulation.java

@@ -1,5 +1,58 @@
-public class Simulation {
+import com.sun.nio.sctp.SctpMultiChannel;
+
+import java.util.stream.Stream;
 
+public class Simulation {
+    private final Bins bins;
+    private final Dice dice;
+    private final int rolls;
+    private final int numDice;
+    public Simulation(int dice, int rolls) {
+        this.numDice = dice;
+        this.dice = new Dice(dice);
+        this.bins = new Bins(dice,dice * 6);
+        this.rolls = rolls;
+    }
+    public void runSimulation(){
+        Stream
+                .iterate(0,q-> q+1)
+                .limit(rolls)
+                .forEach(q-> {
+                    int bin = dice.tossAndSum();
+                    bins.increment(bin);
+                });
+    }
 
+    public String printResults() {
+        StringBuilder sb = new StringBuilder();
+        sb
+                .append("***\n" + "Simulation of ")
+                .append(this.numDice)
+                .append(" dice tossed for ")
+                .append(this.rolls)
+                .append(" times.\n")
+                .append("***\n")
+                .append("\n");
+        Stream
+                .iterate(this.numDice,q -> q + 1)
+                .limit((this.numDice) * 6L - 1)
+                .forEach(q -> {
+                    sb
+                            .append(String.format("%3s",q))
+                            .append(String.format(":%9s",this.bins.getBin(q)))
+                            .append(String.format(":%5.2f ", (double)(this.bins.getBin(q))/(double)(this.rolls)));
+                    Stream
+                            .iterate(0,r->r+1)
+                            .limit(this.bins.getBin(q)/10_000)
+                            .forEach(r -> sb.append("*"));
+                    sb.append("\n");
+                });
+        return sb.toString();
+    }
 
+    public static void main(String[] args) {
+        Simulation sim = new Simulation(2,1_000_000);
+        sim.runSimulation();
+        System.out.println(sim.printResults());
+    }
 }

src/test/java/BinsTest.java

@@ -0,0 +1,28 @@
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Optional;
+import java.util.stream.Stream;
+
+public class BinsTest {
+    private Bins bins;
+    @Before
+    public void setUp(){
+        bins = new Bins(2,12);
+    }
+    @Test
+    public void constructorAndGetTest(){
+        Stream
+                .iterate(2,q -> q+1)
+                .limit(12)
+                .forEach(q-> Assert.assertEquals(Integer.valueOf(0), bins.getBin(q)));
+    }
+    @Test
+    public void incrementTest(){
+        bins.increment(2);
+        Assert.assertEquals(Integer.valueOf(1),bins.getBin(2));
+    }
+
+
+}

src/test/java/DiceTest.java

@@ -0,0 +1,19 @@
+import org.junit.Assert;
+import org.junit.Test;
+
+public class DiceTest {
+    @Test
+    public void constructorTest(){
+        //when
+        Dice dice = new Dice(2);
+        //then
+        Assert.assertEquals(2,dice.getDice().size());
+    }
+    @Test
+    public void tossAndSumTest(){
+        //given
+        Dice dice = new Dice(2);
+        Assert.assertTrue(dice.tossAndSum() >= 2 && dice.tossAndSum() <= 12);
+    }
+
+}

src/test/java/SimulationTest.java

@@ -0,0 +1,16 @@
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class SimulationTest {
+    private Simulation sim;
+    @Before
+    public void setUp(){
+        sim = new Simulation(2,1_000_000);
+    }
+    @Test
+    public void simulatorTest(){
+        sim.runSimulation();
+        Assert.assertNotNull(sim.printResults());
+    }
+}