Add day 2 solutions

day_02/java/Part1.java

@@ -0,0 +1,77 @@
+package day_02.java;
+
+import java.io.FileNotFoundException;
+import java.util.*;
+
+import jlib.FileSystem;
+
+public class Part1 {
+	public static void main(String[] args) {
+		if (args.length < 1) {
+			System.out.println("Not enough args");
+			return;
+		};
+		Scanner s;
+		try {
+			s = FileSystem.readFile(args[0]);
+		} catch (FileNotFoundException e) {
+			System.out.println("Can't find that file");
+			return;
+		}
+
+		Integer points = 0;
+		while (s.hasNextLine()) {
+			String l = s.nextLine();
+			Integer round = Part1.determineScore(
+				l.charAt(l.length() - 1),
+				l.charAt(0)
+			);
+			points = points + round;
+		}
+		System.out.println(points + " points");
+	}
+
+	/**
+	 * Determines if we win or the opponent wins in a game of Rock Paper Scissors
+	 *
+	 * A = Rock
+	 * B = Paper
+	 * C = Scissors
+	 *
+	 * X = Rock
+	 * Y = Paper
+	 * Z = Scissors
+	 *
+	 *      Paper
+	 *     /     ^
+	 *    /       \
+	 *   v         \
+	 * Rock --> Scissors
+	 *
+	 */
+	public static boolean isWin(Character me, Character opponent) {
+		if ( me.equals(opponent) ) {
+			return false;
+		}
+		else if (opponent.equals('A')) {
+			return me.equals('Y');
+		} else if (opponent.equals('B')) {
+			return me.equals('Z');
+		} else {
+			return me.equals('X');
+		}
+	}
+
+	public static Integer determineScore(Character me, Character opponent) {
+		Integer choice = (int)me - 87;
+
+		if (choice == ((int)opponent - 64)) {
+			return 3 + choice;
+		}
+
+		if (Part1.isWin(me, opponent)) {
+			return 6 + choice;
+		}
+		return choice;
+	}
+}