From 312113ce81cd49471ad617e33ac7d8355eb009d2 Mon Sep 17 00:00:00 2001
From: Maya Herrscher <maya.herrscher@gmail.com>
Date: Fri, 15 Dec 2023 23:06:55 +0100
Subject: [PATCH] Bene do stuff

---
 2023/day12/code.py | 55 +++++++++++++++++-----------------------------
 1 file changed, 20 insertions(+), 35 deletions(-)

diff --git a/2023/day12/code.py b/2023/day12/code.py
index bd482dd..57d3e88 100755
--- a/2023/day12/code.py
+++ b/2023/day12/code.py
@@ -1,17 +1,14 @@
 #!/usr/bin/env python3
 
 import sys
-import regex as re
-from itertools import combinations
-from more_itertools import locate
 
 
 def memo(f):
     memo = {}
 
     def f2(x,y):
-        if (x,y) not in memo: memo[(x,y)] = f(x,y)
-        return memo[(x,y)]
+        if (x,tuple(y)) not in memo: memo[(x,tuple(y))] = f(x,tuple(y))
+        return memo[(x,tuple(y))]
     return f2
 
 
@@ -19,37 +16,26 @@ def fulfills(spring, cond):
     return [len(b) for b in spring.split('.') if len(b) > 0] == cond
 
 
-def solve_row1(spring, cond):
-    if len(spring) == (sum(cond) + len(cond) - 1): return 1
-    if fulfills(spring, cond): return 1
-    sols = 0
-    not_dam = spring.count('?') + spring.count('#') - sum(cond)
-    if not_dam < 1: return 0
-    inds = list(locate(spring, lambda x: x == '?'))    
-    for c in combinations(inds, not_dam):
-        rs = list(spring)
-        for i in c:
-            rs[i] = '.'
-        if fulfills(''.join(rs),cond): sols += 1
-    return sols
+def dot(spring, cond):
+    if len(spring) == 0 or spring[0] != '#': return solve_r(spring[1:], cond)
+    else: return 0
+
+
+def hashtag(spring, cond):
+    c = cond[0]
+    if len(spring) < c: return 0
+    for x in range(c):
+        if spring[x] == '.': return 0
+    return dot(spring[c:], cond[1:])
 
 
 @memo
 def solve_r(spring, cond):
-    if cond == '': return 1
-    cond = [int(c) for c in cond.split(',')]
-    spring = spring.strip('.')
-    inds = list(locate(spring, lambda x: x == '.'))    
-    if inds == []:
-        if len(spring) > 10: print(spring, cond)
-        return solve_row1(spring, cond)
-    i = inds[0]
-    sols = 0
-    for j in range(0, len(cond)):
-        if sum(cond[:j]) <= len(list(locate(spring[:i], lambda x: x != '.'))) and sum(cond[j:]) <= len(list(locate(spring[i:], lambda x: x != '.'))):
-            cond1, cond2 = ','.join([str(c) for c in cond[:j]]), ','.join([str(c) for c in cond[j:]])
-            sols += solve_r(spring[:i], cond1) * solve_r(spring[i+1:], cond2)
-    return sols
+    cond = [int(c) for c in cond]
+    if cond == []: return 1 if spring.count('#') == 0 else 0
+    if not '?' in spring: return 1 if fulfills(spring, cond) else 0
+    if spring == '': return 0
+    return dot(spring, cond) + hashtag(spring, cond)
 
 
 if __name__ == '__main__':
@@ -57,9 +43,8 @@ if __name__ == '__main__':
     res1 = 0
     res2 = 0
     for s in springs:
-        res1 += solve_r(*s)
-        res2 += solve_r('?'.join([s[0]]*5),','.join((s[1].split(','))*5))
-        print(solve_r('?'.join([s[0]]*5),','.join((s[1].split(','))*5)))
+        res1 += solve_r(s[0], [int(c) for c in s[1].split(',')])
+        res2 += solve_r('?'.join([s[0]]*5),[int(c) for c in s[1].split(',')*5])
 
     # challenge 1
     res1 = str(res1)