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 +1,64 @@
+package be.vandewalleh.aoc;
+
+import be.vandewalleh.aoc.geometry.Direction2D;
+import be.vandewalleh.aoc.geometry.Point2D;
+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.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+
+@Day(3)
+public class Day03 {
+
+    public static void main(String[] args) {
+        var day = Days.createDay(Day03.class);
+        System.out.println(day.part1());
+        System.out.println(day.part2());
+    }
+
+    private final String[] wireA;
+    private final String[] wireB;
+
+    public Day03(@Lines Input<List<String>> input) {
+        this.wireA = input.getValue().get(0).split(",");
+        this.wireB = input.getValue().get(1).split(",");
+    }
+
+    private List<Point2D> path(String[] wire) {
+        var points = new ArrayList<Point2D>();
+        var point = Point2D.origin;
+        for (var section : wire) {
+            var direction = Direction2D.from(section.charAt(0));
+            var count = Integer.parseInt(section.substring(1));
+            for (int i = 0; i < count; i++) {
+                point = point.translate(direction.point);
+                points.add(point);
+            }
+        }
+        return points;
+    }
+
+    private int part1() {
+        var pathA = path(wireA);
+        var pathB = path(wireB);
+
+        var intersections = new HashSet<>(pathA);
+        intersections.retainAll(pathB);
+
+        return intersections.stream().mapToInt(Point2D::manhattanDistance).min().orElse(-1);
+    }
+
+    private int part2() {
+        var pathA = path(wireA);
+        var pathB = path(wireB);
+
+        var intersections = new HashSet<>(pathA);
+        intersections.retainAll(pathB);
+
+        return intersections.stream().mapToInt(p -> pathA.indexOf(p) + pathB.indexOf(p) + 2).min().orElse(-1);
+    }
+}