Day 3-6 2019

2020-12-31 00:01:58 +01:00
parent 4fef41464e
commit ae327a4928
14 changed files with 1472 additions and 15 deletions
@@ -0,0 +1,81 @@
+package be.vandewalleh.aoc;
+
+import be.vandewalleh.aoc.utils.factory.Days;
+import be.vandewalleh.aoc.utils.input.Day;
+import be.vandewalleh.aoc.utils.input.Input;
+import be.vandewalleh.aoc.utils.input.Lines;
+
+import java.util.*;
+
+@Day(6)
+public class Day06 {
+
+    public static void main(String[] args) {
+        var day = Days.createDay(Day06.class);
+        System.out.println(day.part1());
+        System.out.println(day.part2());
+    }
+
+    private final List<String> input;
+
+    public Day06(@Lines Input<List<String>> input) {
+        this.input = input.getValue();
+    }
+
+    private final Map<String, String> reverseOrbits = new HashMap<>();
+
+    private int countDirectOrbits() {
+        return reverseOrbits.size();
+    }
+
+    private int countIndirectOrbits() {
+        var count = 0;
+        for (var key : reverseOrbits.keySet()) {
+            count += countIndirectOrbits(key);
+        }
+        return count;
+    }
+
+    private int countIndirectOrbits(String key) {
+        var count = 0;
+        var currentKey = reverseOrbits.get(key);
+        while (currentKey != null) {
+            currentKey = reverseOrbits.get(currentKey);
+            if (currentKey != null) count++;
+            else return count;
+        }
+        return -1;
+    }
+
+    private List<String> pathToCom(String key) {
+        var path = new ArrayList<String>();
+        var currentKey = reverseOrbits.get(key);
+        path.add(currentKey);
+        while (currentKey != null) {
+            currentKey = reverseOrbits.get(currentKey);
+            if (currentKey == null) return path;
+            else path.add(currentKey);
+        }
+        return path;
+    }
+
+    private int part1() {
+        for (var line : input) {
+            var split = line.split("\\)");
+            reverseOrbits.put(split[1], split[0]);
+        }
+        return countDirectOrbits() + countIndirectOrbits();
+    }
+
+    private int part2() {
+        var sanPath = pathToCom("SAN");
+        var youPath = pathToCom("YOU");
+
+        var common = new LinkedHashSet<>(sanPath);
+        common.retainAll(youPath);
+
+        String closestCommon = (String) common.toArray()[0];
+        return sanPath.indexOf(closestCommon) + youPath.indexOf(closestCommon);
+    }
+
+}