day 1 in the books

2025-12-01 20:44:46 -05:00
parent 3eb6aa5002
commit b3521f6253
3 changed files with 93 additions and 7 deletions
--- a/src/Day01.java
+++ b/src/Day01.java
@@ -0,0 +1,69 @@
+package src;
+
+import java.io.FileReader;
+import java.util.Scanner;
+
+public class Day01 {
+    public static void main(String[] args) {
+        part1();
+        part2();
+    }
+
+    private static void part1() {
+        try (Scanner scanner = new Scanner(new FileReader("resources/inputs/01/input")).useDelimiter("\\R")) {
+            int dial = 50;
+            int password = 0;
+            while (scanner.hasNext()) {
+                String instruction = scanner.next();
+                int change = Integer.parseInt(instruction.substring(1));
+                switch (instruction.charAt(0)) {
+                    case 'L' -> {
+                        dial = (dial - change + 100) % 100;
+                    }
+                    case 'R' -> {
+                        dial = (dial + change) % 100;
+                    }
+                }
+                if (dial == 0) {
+                    password += 1;
+                }
+            }
+            System.out.println(password);
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    // this is the inefficient way to do it, but it's also accurate!
+    private static void part2() {
+        try (Scanner scanner = new Scanner(new FileReader("resources/inputs/01/input")).useDelimiter("\\R")) {
+            int dial = 50;
+            int password = 0;
+            while (scanner.hasNext()) {
+                String instruction = scanner.next();
+                int change = Integer.parseInt(instruction.substring(1));
+                switch (instruction.charAt(0)) {
+                    case 'L' -> {
+                        for (int i = 0; i < change; i++) {
+                            dial = (dial - 101) % 100;
+                            if (dial == 0) {
+                                password += 1;
+                            }
+                        }
+                    }
+                    case 'R' -> {
+                        for (int i = 0; i < change; i++) {
+                            dial = (dial + 1) % 100;
+                            if (dial == 0) {
+                                password += 1;
+                            }
+                        }
+                    }
+                }
+            }
+            System.out.println(password);
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+    }
+}