2023/day12.py

@@ -2,31 +2,100 @@ import itertools
 import sys
 from collections import defaultdict
 from dataclasses import dataclass
+from typing import Iterator
 
 from tqdm import tqdm
 
 lines = sys.stdin.read().splitlines()
 
+
+def fn1(pattern: str, counts: list[int]) -> Iterator[tuple[str, list[int]]]:
+    if not pattern:
+        yield "", counts
+        return
+
+    if not counts:
+        if pattern.find("#") == -1:
+            yield "." * len(pattern), []
+        return
+
+    if sum(counts) + len(counts) - 1 == len(pattern):
+        c_pattern = ".".join("#" * c for c in counts)
+        if all(pattern[i] == "?" for i in range(len(pattern)) if c_pattern[i] == "."):
+            yield c_pattern, []
+        return
+
+    if pattern.find("#") == -1:
+        yield "." * len(pattern), counts
+
+    if len(pattern) < counts[0]:
+        return
+
+    if pattern.find("?") == -1 and counts[0] == len(pattern):
+        yield pattern, counts[1:]
+
+    for i in range(len(pattern)):
+        c_pattern = "." * i + "#" * counts[0]
+
+        if len(c_pattern) > len(pattern):
+            break
+
+        if len(c_pattern) < len(pattern):
+            c_pattern += "."
+
+        # print(">", c_pattern, counts[0])
+
+        if all(pattern[i] == "?" for i in range(len(c_pattern)) if c_pattern[i] == "."):
+            for other_pattern, other_rest in fn1(pattern[len(c_pattern) :], counts[1:]):
+                # print(">>", other_pattern, other_rest)
+                yield c_pattern + other_pattern, other_rest
+
+
+def fn2(
+    patterns: list[str], counts: list[int], depth: int = 0
+) -> Iterator[tuple[str, ...]]:
+    if not patterns:
+        yield ()
+        return
+
+    with_hash = sum(1 for p in patterns[1:] if p.find("#") >= 0)
+    # print(patterns, counts, with_hash, counts[:-with_hash])
+
+    to_fit = counts if with_hash == 0 else counts[:-with_hash]
+    remaining = [] if with_hash == 0 else counts[-with_hash:]
+
+    for fp, fc in fn1(patterns[0], to_fit):
+        if depth == 0:
+            ...  # print(fp, fc)
+        for fp2 in fn2(patterns[1:], fc + remaining, depth + 1):
+            # print(fp, fc)
+            yield (fp,) + fp2
+
+
+# print(list(fn1("??", [1, 1, 3, 1])))
+# exit()
+
+
+repeat = 5
 count = 0
-for line in lines:
+for i_line, line in enumerate(lines):
     parts = line.split(" ")
-    pattern = parts[0]
+    pattern = "?".join(parts[0] for _ in range(repeat))
-    counts = [int(c) for c in parts[1].split(",")]
+    counts = [int(c) for c in parts[1].split(",")] * repeat
 
-    missing = [i for i in range(len(pattern)) if pattern[i] == "?"]
+    # print("---")
+    # print(i_line, parts[0])
+    # print("--")
+    print("---")
+    print(parts[0], counts[: len(counts) // 5])
+    r1 = list(fn2(list(filter(len, pattern.split("."))), counts))
+    r2 = set(r1)
+    print(len(r1), len(r2))  # , r2)
+    count += len(r1)
 
-    for replacements in itertools.product(".#", repeat=len(missing)):
+    # if i_line == 1:
-        c_pattern = list(pattern)
+    #     break
-        for i_missing, replacement in zip(missing, replacements):
-            c_pattern[i_missing] = replacement
 
-        parts = [p for p in "".join(c_pattern).split(".") if p]
-
-        if len(parts) == len(counts) and all(
-            len(p) == c for p, c in zip(parts, counts)
-        ):
-            # print("".join(c_pattern), counts)
-            count += 1
 
 # part 1
 answer_1 = count
@@ -35,4 +104,3 @@ print(f"answer 1 is {answer_1}")
 # part 2
 answer_2 = ...
 print(f"answer 2 is {answer_2}")
-print(f"answer 2 is {answer_2}")