68 lines
2.3 KiB
Java
68 lines
2.3 KiB
Java
package src;
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import java.io.FileReader;
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import java.time.Duration;
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import java.time.Instant;
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import java.util.Scanner;
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public class Day01 {
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public static void main(String[] args) {
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Instant start = Instant.now();
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part1();
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Instant middle = Instant.now();
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part2();
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Instant end = Instant.now();
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IO.println("part 1: " + Duration.between(start, middle).toMillis() + " ms");
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IO.println("part 2: " + Duration.between(middle, end).toMillis() + " ms");
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}
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private static void part1() {
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try (Scanner scanner = new Scanner(new FileReader("resources/inputs/01/input"))) {
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int dial = 50;
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int password = 0;
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while (scanner.hasNextLine()) {
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String instruction = scanner.nextLine();
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int change = Integer.parseInt(instruction.substring(1));
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int step = switch (instruction.charAt(0)) {
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case 'L' -> -1;
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case 'R' -> 1;
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default -> 0; // impossible
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};
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dial = (dial + change * step) % 100;
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if (dial == 0) {
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password += 1;
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}
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}
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System.out.println(password);
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} catch (Exception e) {
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System.out.println(e.getMessage());
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}
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}
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// this is the inefficient way to do it, but it's also accurate!
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private static void part2() {
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try (Scanner scanner = new Scanner(new FileReader("resources/inputs/01/input"))) {
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int dial = 50;
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int password = 0;
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while (scanner.hasNextLine()) {
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String instruction = scanner.nextLine();
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int change = Integer.parseInt(instruction.substring(1));
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int step = switch (instruction.charAt(0)) {
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case 'L' -> -1;
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case 'R' -> 1;
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default -> 0; // impossible
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};
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for (int i = 0; i < change; i++) {
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dial = (dial + step) % 100;
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if (dial == 0) {
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password += 1;
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}
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}
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}
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System.out.println(password);
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} catch (Exception e) {
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System.out.println(e.getMessage());
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}
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}
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}
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