Initial commit

.gitignore

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+build/
+.gradle/

README.md

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+# 2019  AP Computer Science A FRQ #4 LightBoard
+Instructions:  https://apstudents.collegeboard.org/ap/pdf/ap19-frq-computer-science-a.pdf 
+
+Quick Reference Guide:  https://apstudents.collegeboard.org/ap/pdf/ap-computer-science-a-java-quick-reference.pdf 
+
+The correct answer outputs should have a pattern of 7 rows and 5 columns of stars and dots **_similar_** to that shown and should match the last line exactly.   
+
+
+
+```
+**.*.
+***..
+.**..
+****.
+**...
+.....
+....*
+
+
+false true false true
+```

build.gradle

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+plugins {
+	id 'java'
+}
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	testImplementation('org.junit.jupiter:junit-jupiter:5.6.0')
+}
+
+test {
+	useJUnitPlatform()
+	testLogging {
+		events "passed", "skipped", "failed"
+	}
+}

src/main/java/LightBoard.java

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+public class LightBoard
+{
+  /** The lights on the board, where true represents on and false represents off.
+   */
+  private boolean[][] lights;
+
+  /** Constructs a LightBoard object having numRows rows and numCols columns.
+   * Precondition: numRows > 0, numCols > 0
+   * Postcondition: each light has a 40% probability of being set to on.
+   */
+  public LightBoard(int numRows, int numCols)
+  {
+    /* to be implemented in part (a) */
+
+  }
+
+  /** Evaluates a light in row index row and column index col and returns a status
+   *  as described in part (b).
+   *  Precondition: row and col are valid indexes in lights.
+   */
+  public boolean evaluateLight(int row, int col)
+  {
+    /* to be implemented in part (b) */
+
+
+  }
+  public boolean[][] getLights()
+  {
+    return lights;
+  }
+  //used for testing
+  public String toString()
+  {
+    String s = "";
+    for (int r = 0; r < lights.length; r++)
+    {
+      for (int c = 0; c < lights[0].length; c++)
+        if (lights[r][c])
+          s += "*";
+        else
+          s += ".";
+      s += "\n";
+    }
+    return s;
+  }
+
+}

src/main/java/Main.java

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+public class Main {
+ public static void main(String[] args)
+  {
+    LightBoard sim = new LightBoard(7, 5);
+    System.out.println(sim);
+    System.out.println();
+
+    String[] stars = {"**.**", "*..*.", "*..**", "*...*", "*...*", "**.**", "....."};
+    boolean[][] lights = sim.getLights();
+    for (int r = 0; r < stars.length; r++)
+      for (int c = 0; c < stars[0].length(); c++)
+        lights[r][c] = stars[r].charAt(c) == '*';
+    System.out.println(sim.evaluateLight(0, 3) + " " + sim.evaluateLight(6, 0) + " " +
+                       sim.evaluateLight(4, 1) + " " + sim.evaluateLight(5, 4));
+    System.out.println();
+  }
+}

src/test/java/Tester.java

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+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import java.io.*;
+
+public class Tester {
+
+   @Test
+   public void partA () {
+      LightBoard test = new LightBoard(500,650);
+      int rows = test.getLights().length;
+      int cols = test.getLights()[0].length;
+      assertEquals(500,rows);
+      assertEquals(650,cols);
+      // double count = 0;
+      // for(int r = 0; r < rows;r++)
+      //   for(int c = 0; c < cols; c++)
+      //     if(test.getLights()[r][c])
+      //       count++;
+      // assertEquals(0.4,count/(rows*cols),0.2);
+      // Don't think you can test this since it's random
+   }
+
+   @Test
+   public void partB(){
+      LightBoard test = new LightBoard(7,5);
+      String[] stars = {"**.**", "*..*.", "*..**", "*...*", "*...*", "**.**", "....."};
+      boolean[][] newLights = test.getLights();
+      for (int r = 0; r < stars.length; r++)
+         for (int c = 0; c < stars[0].length(); c++)
+           newLights[r][c] = stars[r].charAt(c) == '*';
+      assertEquals(false,test.evaluateLight(0, 3),partBFail(false,0,3));
+      assertEquals(true,test.evaluateLight(6, 0),partBFail(true,6,0));
+      assertEquals(false,test.evaluateLight(4, 1),partBFail(false,4,1));
+      assertEquals(true,test.evaluateLight(5, 4),partBFail(true,5,4));
+   }
+
+   private String partBFail(boolean expected, int num1, int num2){
+      return "Expected " + expected + " with evaluateLight(" + num1 + "," + num2 + "), but output was " + !expected;
+   }
+
+
+}