Solve 2015 days 8-10.

2015/d10.py

@@ -0,0 +1,35 @@
+from functools import lru_cache
+data = open(0).read().strip()
+
+part_1 = False
+if part_1:
+    repeats = 40
+else:
+    repeats = 50
+
+@lru_cache
+def look_and_say(data: str) -> str:
+    r = ""
+    i = 0
+    while i < len(data):
+        count = 0
+        c = data[i]
+        while i < len(data) and data[i] == c:
+            count += 1
+            i += 1
+        r += f"{count}{c}"
+    return r
+
+CHUNK_SIZE = 10000
+for _ in range(repeats):
+    ndata = ""
+    lo, up = 0, CHUNK_SIZE
+    while up < len(data):
+        while up < len(data) and data[up - 1] == data[up]:
+            up += 1
+        ndata += look_and_say(data[lo:up])
+        lo, up = up, up + CHUNK_SIZE
+    ndata += look_and_say(data[lo:up])
+    data = ndata
+
+print(len(data))