Solve day 14 2015 part 2: Reindeer Olympics

Author: SimonBaars

src/main/java/com/sbaars/adventofcode/year15/days/Day14.java

@@ -20,6 +20,7 @@ public static void main(String[] args) {
  Day14 day = new Day14();
  day.printParts();
  new com.sbaars.adventofcode.network.Submit().submit(day.part1(), 2015, 14, 1);
+ new com.sbaars.adventofcode.network.Submit().submit(day.part2(), 2015, 14, 2);
  }
 
  private void parseInput() {
@@ -46,7 +47,27 @@ public Object part1() {
 
  @Override
  public Object part2() {
- return 0; // Implement in next part
+ Map<Reindeer, Integer> points = reindeers.stream()
+ .collect(Collectors.toMap(r -> r, r -> 0));
+ 
+ // For each second
+ for (int second = 1; second <= RACE_DURATION; second++) {
+ final int currentSecond = second;
+ int maxDistance = reindeers.stream()
+ .mapToInt(r -> r.getDistanceAfter(currentSecond))
+ .max()
+ .orElse(0);
+ 
+ // Award points to all reindeers in the lead
+ reindeers.stream()
+ .filter(r -> r.getDistanceAfter(currentSecond) == maxDistance)
+ .forEach(r -> points.merge(r, 1, Integer::sum));
+ }
+ 
+ return points.values().stream()
+ .mapToInt(Integer::intValue)
+ .max()
+ .orElse(0);
  }
 
  private static class Reindeer {