day 7 refactor

7/a.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+
+from collections import defaultdict
+
+
+def main():
+    relations = defaultdict(lambda: set())  # mapping of step ID to what theyre blocked by
+    steps = set()
+
+    with open("input.txt") as f:
+        for line in f.readlines():
+            _, stepid, _, _, _, _, _, blocks, _, _ = line.split()
+            relations[blocks].update([stepid])
+            steps.update([blocks, stepid])
+
+    remaining = sorted(list(steps))
+    complete = set()
+
+    while remaining:
+        for step in remaining[:]:
+            # find unblocked step
+            if not relations[step]:
+                print(step, end="")
+                complete.update(step)
+                # remove the completed step from the blockers of other steps
+                for k, v in relations.items():
+                    if step in v:
+                        v.remove(step)
+                remaining.remove(step)
+                break
+    print()
+
+
+if __name__ == '__main__':
+    main()

7/b.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+
+
+class Job(object):
+    def __init__(self, id, reqs, duration):
+        self.id = id
+        self.reqs = reqs
+        self.duration = duration
+
+    def __repr__(self):
+        return "<Job '{}'' ({}s) reqs:{}>".format(self.id, self.duration, self.reqs)
+
+
+class Worker(object):
+    def __init__(self):
+        self.task = None
+        self.busy = 0
+
+    def __repr__(self):
+        return "<Worker {} (busy for {}s) (job:{})>".format(id(self), self.busy, self.task)
+
+
+def main():
+    num_workers = 5
+    workers = [Worker() for i in range(0, num_workers)]
+
+    jobs = {}
+
+    def makejob(jobid):
+        if jobid not in jobs:
+            jobs[jobid] = Job(jobid, set(), ord(jobid) - 64 + 60)
+
+    with open("input.txt") as f:
+        for line in f.readlines():
+            _, stepid, _, _, _, _, _, blocks, _, _ = line.split()
+            makejob(stepid)
+            makejob(blocks)
+            jobs[blocks].reqs.update([stepid])
+
+    duration = 0  # the answer
+    completed = set()
+    while True:
+        # do worker accounting
+        remainings = [worker.busy for worker in workers if worker.task is not None]
+
+        # find the next worker(s) to complete
+        if remainings:
+            next_done = min(remainings)
+
+            # fast-forward time to that point
+            duration += next_done
+            for worker in workers:
+                if worker.task:
+                    worker.busy -= next_done
+                    if worker.busy == 0:
+                        print("finished task:", worker.task)
+                        completed.update([worker.task.id])
+                        worker.task = None
+
+        if not jobs and all([worker.task is None for worker in workers]):
+            break
+
+        # find available tasks
+        available = [task for taskid, task in jobs.items() if task.reqs.issubset(completed)]
+
+        # sort by weight
+        available.sort(key=lambda x: x.duration)
+
+        # assign tasks to available workers
+        for worker in workers:
+            if worker.task is None:
+                if not available:
+                    break
+                task = available.pop()
+                worker.task = task
+                worker.busy = task.duration
+                print("assigned", task, "to", worker)
+                del jobs[task.id]  # remove job from work queue
+
+    print(duration)
+
+
+if __name__ == '__main__':
+    main()