Solve day 7 and 8 of 2018.

2018/d7.py

@@ -1,12 +1,71 @@
-from lib import str_to_ints
+from lib import LETTERS_UPPER
 
 
 def part_1(data):
-    print(data)
+    deps = {c: [] for c in LETTERS_UPPER}
+    for line in data.splitlines():
+        fields = line.split()
+        a, b = fields[1], fields[7]
+        deps[b].append(a)
+    ready = []
+    for x, ys in deps.items():
+        if len(ys) == 0:
+            ready.append(x)
+    seq = []
+    ready = sorted(ready)
+    while ready:
+        current, ready = ready[0], ready[1:]
+        seq.append(current)
+        for x, ys in deps.items():
+            if current in ys:
+                ys.remove(current)
+                if len(ys) == 0:
+                    ready.append(x)
+                    ready = sorted(ready)
+
+    print("".join(seq))
+
+
+def score(c):
+    return 1 + ord(c) - ord("A") + 60
 
 
 def part_2(data):
-    pass
+    deps = {c: [] for c in LETTERS_UPPER}
+    for line in data.splitlines():
+        fields = line.split()
+        a, b = fields[1], fields[7]
+        deps[b].append(a)
+
+    ready = []
+    done = []
+    for x, ys in deps.items():
+        if len(ys) == 0:
+            ready.append(x)
+    workers = {}
+
+    steps = 0
+    while len(done) != 26:
+        ready = sorted(ready)
+        while len(ready) > 0 and len(workers) < 5:
+            current, ready = ready[0], ready[1:]
+            workers[current] = score(current)
+
+        to_del = []
+        for k in workers.keys():
+            workers[k] -= 1
+            if workers[k] == 0:
+                to_del.append(k)
+                done.append(k)
+                for x, ys in deps.items():
+                    if k in ys:
+                        ys.remove(k)
+                        if len(ys) == 0:
+                            ready.append(x)
+        for k in to_del:
+            del workers[k]
+        steps += 1
+    print(steps)
 
 
 def main():

2018/d8.py

@@ -0,0 +1,59 @@
+from lib import *
+
+
+def parse(fields, i):
+    n_children = fields[i]
+    n_meta = fields[i + 1]
+    i += 2
+    children = []
+    meta_score = 0
+    for _ in range(n_children):
+        c, i, m = parse(fields, i)
+        children.append(c)
+        meta_score += m
+    for i in range(i, i + n_meta):
+        meta_score += fields[i]
+    i += 1
+    return children, i, meta_score
+
+
+def parse2(fields, i):
+    n_children = fields[i]
+    n_meta = fields[i + 1]
+    i += 2
+    children = []
+    scores = []
+    for _ in range(n_children):
+        c, i, s = parse2(fields, i)
+        children.append(c)
+        scores.append(s)
+
+    score = 0
+    if n_children == 0:
+        for j in range(i, i + n_meta):
+            score += fields[j]
+    else:
+        for j in range(i, i + n_meta):
+            new_i = fields[j]
+            new_i -= 1
+            if new_i < 0:
+                continue
+            if new_i < len(children):
+                score += scores[new_i]
+    i += n_meta
+    return children, i, score
+
+
+def main():
+    input_file = __file__.replace(".py", ".txt")
+    with open(input_file) as f:
+        data = f.read()
+    nums = str_to_ints(data)
+    tree = parse(nums, 0)
+    print(tree[2])
+    tree = parse2(nums, 0)
+    print(tree[2])
+
+
+if __name__ == "__main__":
+    main()

README.md

@@ -95,4 +95,6 @@ written in Python.
 - Day 4: 25:16
 - Day 5: 17:03
 - Day 6: 1:10:29
-- Day 7:
+- Day 7: 20:15
+- Day 8: 18:35
+- Day 9: