Solve 2024 day 7

2024/d6.py

@@ -0,0 +1,51 @@
+from lib import get_data
+from lib import Grid2D
+
+data = get_data(__file__)
+
+
+DIRS = [
+    (-1, 0),
+    (0, 1),
+    (1, 0),
+    (0, -1),
+]
+
+g = Grid2D(data)
+
+t = 0
+for rr in range(g.n_rows):
+    for cc in range(g.n_cols):
+        (p,), dir = g.find("^"), 0
+        seen = set()
+        loop = False
+
+        if g[(rr, cc)] == "#":
+            continue
+
+        if g[(rr, cc)] != "^":
+            g[(rr, cc)] = "#"
+
+        while True:
+            if (p, dir) in seen:
+                loop = True
+                break
+            seen.add((p, dir))
+            r, c = p[0] + DIRS[dir][0], p[1] + DIRS[dir][1]
+            if not (0 <= r < g.n_rows and 0 <= c < g.n_cols):
+                break
+
+            if g[(r, c)] == "#":
+                dir = (dir + 1) % 4
+            else:
+                p = (r, c)
+
+        if g[(rr, cc)] == "^":
+            print(len(set(pos for pos, _ in seen)))
+        else:
+            g[(rr, cc)] = "."
+
+        if loop:
+            t += 1
+
+print(t)

2024/d7.py

@@ -0,0 +1,43 @@
+from lib import get_data
+from lib import Grid2D
+from lib import ints
+from collections import defaultdict
+
+data = """ 190: 10 19
+3267: 81 40 27
+83: 17 5
+156: 15 6
+7290: 6 8 6 15
+161011: 16 10 13
+192: 17 8 14
+21037: 9 7 18 13
+292: 11 6 16 20
+"""
+
+data = get_data(__file__)
+
+
+def comp(acc, rest, part_2=False):
+    if rest == []:
+        return acc
+
+    nacc = []
+    for a in acc:
+        nacc.append(a + rest[0])
+        nacc.append(a * rest[0])
+        if part_2:
+            nacc.append(int(str(a) + str(rest[0])))
+    return comp(nacc, rest[1:], part_2)
+
+
+t1, t2 = 0, 0
+for line in data.splitlines():
+    xs = ints(line)
+    expected = xs[0]
+    if xs[0] in comp([xs[1]], xs[2:]):
+        t1 += xs[0]
+    if xs[0] in comp([xs[1]], xs[2:], True):
+        t2 += xs[0]
+
+print(t1)
+print(t2)

README.md

@@ -296,3 +296,6 @@ and focus. Of course, learning more algorithms and techniques helps.
 - Day 3: `00:01:48   165      0   00:02:40    56     45`
 - Day 4: `00:07:47  1101      0   00:24:07  2410      0`
 - Day 5: `00:07:07   679      0   00:23:02  1998      0`
+- Day 6: `00:09:43  1082      0   00:16:29   464      0`
+- Day 7: `00:12:29  2058      0   00:13:08  1170      0`
+- Day 8: