Do days 5 and 6.

d4.py

@@ -1,36 +1,65 @@
+from string import ascii_lowercase, ascii_uppercase, digits
 import re
 
 EXAMPLE = """
-
+Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11
 """
 
 def clean(text: str) -> list[str]:
     return list(filter(lambda l: l.strip() != "", text.splitlines()))
 
 def solve(lines: list[str]):
-    s = 0
+    res = 0
     for (i, line) in enumerate(lines):
-        print(i, line)
-    return s
+        c, s = line.split(":")
+        w, y = s.split("|")
+        w = set([int(c) for c in w.strip().split()])
+        y = set([int(c) for c in y.strip().split()])
+        z = w.intersection(y)
+
+        if z:
+            ps = 1
+        else:
+            ps = 0
+        for _ in range(len(z) - 1):
+            ps *= 2
+        res += ps
+    return res
 
 def solve2(lines: list[str]):
-    s = 0
+    res = 0
+    matches = []
     for (i, line) in enumerate(lines):
-        print(i, line)
-    return s
+        c, s = line.split(":")
+        w, y = s.split("|")
+        w = set([int(c) for c in w.strip().split()])
+        y = set([int(c) for c in y.strip().split()])
+        z = w.intersection(y)
+        matches.append(len(z))
+
+    scratchcards = list(range(len(matches)))
+    while scratchcards:
+        sc = scratchcards.pop()
+        res += 1
+        for i in range(matches[sc]):
+            if sc + i + 1 < len(matches):
+                scratchcards.append(sc + i + 1)
+    return res
 
 def main():
     example = clean(EXAMPLE)
     print("Example  1:", solve(example))
-    return
 
     data = clean(open("i4.txt").read())
     print("Solution 1:", solve(data))
-    return
 
     example = clean(EXAMPLE)
     print("Example  2:", solve2(example))
-    return
 
     data = clean(open("i4.txt").read())
     print("Solution 2:", solve2(data))