1 files changed, 38 insertions, 0 deletions
diff --git a/2024/13/python/main.py b/2024/13/python/main.py
new file mode 100644
index 0000000..de31184
--- /dev/null
+++ b/2024/13/python/main.py
@@ -0,0 +1,38 @@
+import re
+from fileinput import input
+from itertools import batched
+
+lines = [line.strip() for line in input()]
+
+
+re_button = r"Button [A|B]: X\+(\d+), Y\+(\d+)"
+re_prize = r"Prize: X=(\d+), Y=(\d+)"
+
+
+def solve(machine, gold):
+    m = re.fullmatch(
+        r"Button A: X\+(\d+), Y\+(\d+)Button B: X\+(\d+), Y\+(\d+)Prize: X=(\d+), Y=(\d+)",
+        "".join(machine),
+    )
+    # 2x2 matrix solve
+    ax, ay, bx, by, px, py = map(int, m.groups())
+    if gold:
+        px += 10000000000000
+        py += 10000000000000
+    det = ax * by - ay * bx
+
+    A = (by * px - bx * py) / det
+    B = (-ay * px + ax * py) / det
+
+    # Check solutions are ints
+    if abs(int(A) - A) < 1e-7 and abs(int(B) - B) < 1e-7:
+        return 3 * int(A) + int(B)
+    else:
+        return 0
+
+
+silver = sum(solve(b, False) for b in batched(lines, 4))
+gold = sum(solve(b, True) for b in batched(lines, 4))
+
+print("silver:", silver)
+print("gold:", gold)