Quick and dirty day 7.

This code was brought to you by insomnia.

data/07.txt

@@ -0,0 +1,101 @@
+Step F must be finished before step N can begin.
+Step V must be finished before step Y can begin.
+Step B must be finished before step W can begin.
+Step K must be finished before step O can begin.
+Step E must be finished before step H can begin.
+Step A must be finished before step P can begin.
+Step Y must be finished before step S can begin.
+Step T must be finished before step L can begin.
+Step G must be finished before step R can begin.
+Step I must be finished before step H can begin.
+Step X must be finished before step M can begin.
+Step N must be finished before step C can begin.
+Step O must be finished before step R can begin.
+Step Z must be finished before step R can begin.
+Step R must be finished before step D can begin.
+Step M must be finished before step C can begin.
+Step H must be finished before step D can begin.
+Step C must be finished before step U can begin.
+Step J must be finished before step D can begin.
+Step L must be finished before step Q can begin.
+Step D must be finished before step U can begin.
+Step S must be finished before step U can begin.
+Step U must be finished before step Q can begin.
+Step P must be finished before step Q can begin.
+Step W must be finished before step Q can begin.
+Step X must be finished before step R can begin.
+Step P must be finished before step W can begin.
+Step B must be finished before step U can begin.
+Step E must be finished before step J can begin.
+Step T must be finished before step R can begin.
+Step M must be finished before step L can begin.
+Step M must be finished before step P can begin.
+Step V must be finished before step T can begin.
+Step T must be finished before step U can begin.
+Step R must be finished before step W can begin.
+Step V must be finished before step A can begin.
+Step X must be finished before step S can begin.
+Step V must be finished before step U can begin.
+Step C must be finished before step P can begin.
+Step J must be finished before step S can begin.
+Step F must be finished before step D can begin.
+Step Y must be finished before step U can begin.
+Step L must be finished before step W can begin.
+Step F must be finished before step T can begin.
+Step B must be finished before step E can begin.
+Step F must be finished before step J can begin.
+Step R must be finished before step M can begin.
+Step Z must be finished before step W can begin.
+Step K must be finished before step E can begin.
+Step S must be finished before step W can begin.
+Step U must be finished before step P can begin.
+Step S must be finished before step P can begin.
+Step D must be finished before step W can begin.
+Step Z must be finished before step P can begin.
+Step U must be finished before step W can begin.
+Step M must be finished before step J can begin.
+Step M must be finished before step W can begin.
+Step H must be finished before step U can begin.
+Step E must be finished before step C can begin.
+Step C must be finished before step Q can begin.
+Step L must be finished before step U can begin.
+Step Y must be finished before step R can begin.
+Step E must be finished before step D can begin.
+Step A must be finished before step S can begin.
+Step Z must be finished before step J can begin.
+Step X must be finished before step W can begin.
+Step C must be finished before step D can begin.
+Step C must be finished before step S can begin.
+Step G must be finished before step N can begin.
+Step K must be finished before step Z can begin.
+Step T must be finished before step I can begin.
+Step H must be finished before step W can begin.
+Step E must be finished before step Q can begin.
+Step R must be finished before step J can begin.
+Step O must be finished before step H can begin.
+Step O must be finished before step J can begin.
+Step L must be finished before step S can begin.
+Step A must be finished before step H can begin.
+Step K must be finished before step G can begin.
+Step I must be finished before step X can begin.
+Step T must be finished before step W can begin.
+Step O must be finished before step W can begin.
+Step N must be finished before step Q can begin.
+Step V must be finished before step Z can begin.
+Step H must be finished before step S can begin.
+Step F must be finished before step L can begin.
+Step X must be finished before step Z can begin.
+Step I must be finished before step U can begin.
+Step T must be finished before step J can begin.
+Step G must be finished before step S can begin.
+Step E must be finished before step U can begin.
+Step M must be finished before step U can begin.
+Step J must be finished before step U can begin.
+Step E must be finished before step P can begin.
+Step F must be finished before step C can begin.
+Step O must be finished before step Q can begin.
+Step D must be finished before step Q can begin.
+Step A must be finished before step L can begin.
+Step H must be finished before step J can begin.
+Step I must be finished before step P can begin.
+Step Y must be finished before step D can begin.

day07.nim

@@ -0,0 +1,60 @@
+import sequtils, strutils
+
+var
+    dependencies: array[26, array[27, bool]]
+
+for line in readFile("data/07.txt").strip.splitlines:
+    dependencies[ord(line[36]) - 65][ord(line[5]) - 64] = true
+
+func next_task(status: array[26, array[27, bool]]): int =
+    var falses: array[27, bool]
+    status.find(falses)
+
+func execute(status: ptr array[26, array[27, bool]], action: int) =
+    status[action][0] = true
+    for i in 0..25:
+        status[i][action + 1] = false
+
+func part1(dependencies: array[26, array[27, bool]]): string =
+    var status: array[26, array[27, bool]]
+    status.deepCopy(dependencies)
+    for i in 0..25:
+        var task = status.next_task
+        status.addr.execute(task)
+        result &= chr(task + 65)
+
+func part2(dependencies: array[26, array[27, bool]]): int =
+    var
+        status: array[26, array[27, bool]]
+        worker_times: array[5, int]
+        task_times: array[26, int]
+        completed = ""
+        time = 0
+
+    status.deepCopy(dependencies)
+
+    while len(completed) < 26:
+        time += 1
+        for i in 0..25:
+            if task_times[i] == 1:
+                task_times[i] = 0
+                completed &= chr(i + 65)
+                status.addr.execute(i)
+            elif task_times[i] > 1:
+                task_times[i] -= 1
+
+        for i in 0..4:
+            if worker_times[i] > 0:
+                worker_times[i] -= 1
+            
+            if worker_times[i] == 0:
+                var task = status.next_task
+                if task > -1:
+                    worker_times[i] = 61 + task
+                    task_times[task] = 61 + task
+                    status[task][0] = true
+
+    time - 1
+
+echo dependencies.part1
+echo dependencies.part2