Initial commit

.gitignore

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+build/
+.gradle/

README.md

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+# 2019  AP Computer Science A FRQ #1 APCalendar
+
+Instructions:  [https://apstudents.collegeboard.org/ap/pdf/ap19-frq-computer-science-a.pdf](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](https://apstudents.collegeboard.org/ap/pdf/ap-computer-science-a-java-quick-reference.pdf) 
+
+ The correct answer outputs should be as follows.   
+
+
+
+```
+1999 Feb 5 5 Nov 15 1
+2000 Feb 5 6 Nov 15 3
+2001 Feb 5 1 Nov 15 4
+2002 Feb 5 2 Nov 15 5
+2003 Feb 5 3 Nov 15 6
+2004 Feb 5 4 Nov 15 1
+2005 Feb 5 6 Nov 15 2
+2006 Feb 5 0 Nov 15 3
+2007 Feb 5 1 Nov 15 4
+```

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/APCalendar.java

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+public class APCalendar
+{
+  /** Returns true if year is a leap year and false otherwise. */
+  private static boolean isLeapYear(int year)
+  {
+    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
+  }
+
+
+  /** Returns the number of leap years between year1 and year2, inclusive.
+   * Precondition: 0 <= year1 <= year2
+   */
+  public static int numberOfLeapYears(int year1, int year2)
+  { 
+    /* to be implemented in part (a) */
+
+  }
+
+  /** Returns the value representing the day of the week for the first day of year,
+   *  where 0 denotes Sunday, 1 denotes Monday, ..., and 6 denotes Saturday.
+   */
+  private static int firstDayOfYear(int year)
+  {
+    /* January 1, 1980 was a Tuesday */
+      return (2 + 365*(year - 1980) + numberOfLeapYears(1980, year-1)) % 7;
+  }
+
+  /** Returns n, where month, day, and year specify the nth day of the year.
+   *  Returns 1 for January 1 (month = 1, day = 1) of any year.
+   *  Precondition: The date represented by month, day, year is a valid date.
+   */
+  private static int dayOfYear(int month, int day, int year)
+  {
+    final int[] daysInMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+    int n = day;
+    int mth  = 1;
+    while (mth < month)
+    {
+      n += daysInMonth[mth - 1];
+      mth++;
+    }
+    if (mth > 2 && isLeapYear(year))
+      n++;
+    return n;
+  }
+
+  /** Returns the value representing the day of the week for the given date
+   *  (month, day, year), where 0 denotes Sunday, 1 denotes Monday, ...,
+   *  and 6 denotes Saturday.
+   *  Precondition: The date represented by month, day, year is a valid date.
+   */
+  public static int dayOfWeek(int month, int day, int year)
+  {
+    /* to be implemented in part (b) */
+  }
+}

src/main/java/Main.java

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+public class Main {
+  public static void main(String[] args)
+  {
+    for (int year = 1999; year <= 2007; year++)
+      System.out.println(year + " Feb 5 " + APCalendar.dayOfWeek(2, 5, year) +
+                                " Nov 15 " + APCalendar.dayOfWeek(11, 15, year));
+
+    /*
+      1999 Feb 5 5 Nov 15 1
+      2000 Feb 5 6 Nov 15 3
+      2001 Feb 5 1 Nov 15 4
+      2002 Feb 5 2 Nov 15 5
+      2003 Feb 5 3 Nov 15 6
+      2004 Feb 5 4 Nov 15 1
+      2005 Feb 5 6 Nov 15 2
+      2006 Feb 5 0 Nov 15 3
+      2007 Feb 5 1 Nov 15 4
+    */
+  }
+}

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 () {
+      int result = APCalendar.numberOfLeapYears(0,2000);
+      assertEquals(486,result);
+      result = APCalendar.numberOfLeapYears(1950,1960);
+      assertEquals(3,result);
+      result = APCalendar.numberOfLeapYears(1900,2020);
+      assertEquals(30,result);
+      result = APCalendar.numberOfLeapYears(2000,2021);
+      assertEquals(6,result);
+   }
+   @Test
+   public void partB(){
+      /*
+      1999 Feb 5 5 Nov 15 1   2000 Feb 5 6 Nov 15 3
+      2001 Feb 5 1 Nov 15 4   2002 Feb 5 2 Nov 15 5
+      2003 Feb 5 3 Nov 15 6   2004 Feb 5 4 Nov 15 1
+      2005 Feb 5 6 Nov 15 2   2006 Feb 5 0 Nov 15 3
+      2007 Feb 5 1 Nov 15 4
+    */
+       int result = APCalendar.dayOfWeek(2,5,1999);
+       assertEquals(5,result);
+       result = APCalendar.dayOfWeek(11,15,1999);
+       assertEquals(1,result);
+       result = APCalendar.dayOfWeek(2,5,2000);
+       assertEquals(6,result);
+       result = APCalendar.dayOfWeek(11,15,2000);
+       assertEquals(3,result);
+       result = APCalendar.dayOfWeek(2,5,2001);
+       assertEquals(1,result);
+       result = APCalendar.dayOfWeek(11,15,2001);
+       assertEquals(4,result);
+       result = APCalendar.dayOfWeek(2,5,2002);
+       assertEquals(2,result);
+       result = APCalendar.dayOfWeek(11,15,2002);
+       assertEquals(5,result);
+   }
+
+
+}