day13 - try to naively implement the equation solver instead of relying on external libraries; can't be *that* hard, right? RIGHT?

day13.py

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+# from sympy import solve
+# from sympy.abc import x, y
+from math import lcm
+from tools.aoc import AOCDay
+from typing import Any
+
+BLOWUP_FACTOR = 10_000_000_000_000
+
+
+def solve(machine: tuple[tuple[int, int], tuple[int, int], tuple[int, int]], part2: bool = False) -> tuple[int, int]:
+    # ax + by = c
+    # y = (c - ax) / b
+    lcm_a = lcm(machine[0][0], machine[1][0])
+    tmb_one = lcm_a / machine[0][0]
+    tmb_two = lcm_a / machine[1][0]
+    a1 = machine[0][0] * tmb_one
+    a2 = machine[1][0] * tmb_two
+    b1 = machine[0][1] * tmb_one
+    b2 = machine[1][1] * tmb_two
+    if not part2:
+        c1 = machine[2][0] * tmb_one
+        c2 = machine[2][1] * tmb_two
+    else:
+        c1 = (machine[2][0] + BLOWUP_FACTOR) * tmb_one
+        c2 = (machine[2][1] + BLOWUP_FACTOR) * tmb_two
+
+    ratio_a = a1 / a2
+    ratio_b = b1 / b2
+    ratio_c = c1 / c2
+
+    if ratio_a == ratio_b == ratio_c:
+        return -1, -1  # infinite many solutions
+    elif ratio_a == ratio_b and ratio_b != ratio_c:
+        return -1, -1  # no solutions
+    else:
+        y = (c1 - c2) / (b1 - b2)
+        x = (c1 - (b1 * y)) / a1
+        return x, y
+
+    pass
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (480, "input13_test"),
+            (33427, "input13"),
+        ],
+        [
+            (91649162972270, "input13"),
+        ],
+    ]
+
+    def parse_input(self) -> list[tuple[tuple[int, int], tuple[int, int], tuple[int, int]]]:
+        machines = []
+        for machine in self.getMultiLineInputAsArray():
+            button_a = machine[0].split(": ")[1]
+            button_a_x, button_a_y = (int(x[2:]) for x in button_a.split(", "))
+            button_b = machine[1].split(": ")[1]
+            button_b_x, button_b_y = (int(x[2:]) for x in button_b.split(", "))
+            prize = machine[2].split(": ")[1]
+            prize_x, prize_y = (int(x[2:]) for x in prize.split(", "))
+
+            machines.append(((button_a_x, button_a_y), (button_b_x, button_b_y), (prize_x, prize_y)))
+
+        return machines
+
+    def part1(self) -> Any:
+        tokens = 0
+        for machine in self.parse_input():
+            x, y = solve(machine)
+            if x > 0 and y > 0:
+                print(machine, x, y, 3 * x + y)
+                tokens += 3 * x + y
+        return tokens
+        #    found = False
+        #    for ba_press in range(100):
+        #        for bb_press in range(100):
+        #            if (
+        #                ba_press * machine[0][0] + bb_press * machine[1][0] == machine[2][0]
+        #                and ba_press * machine[0][1] + bb_press * machine[1][1] == machine[2][1]
+        #            ):
+        #                tokens += 3 * ba_press + bb_press
+        #                found = True
+        #                break
+
+        #        if found:
+        #           break
+
+        # return tokens
+
+    def part2(self) -> Any:
+        tokens = 0
+        # for machine in self.parse_input():
+        #    ans = solve(
+        #        [
+        #            machine[0][0] * x + machine[1][0] * y - (machine[2][0] + BLOWUP_FACTOR),
+        #            machine[0][1] * x + machine[1][1] * y - (machine[2][1] + BLOWUP_FACTOR),
+        #        ],
+        #        [x, y],
+        #        dict=True,
+        #    )
+        #    if len(ans) == 1 and ans[0][x] == int(ans[0][x]) and ans[0][y] == int(ans[0][y]):
+        #        tokens += 3 * ans[0][x] + ans[0][y]
+
+        return tokens
+
+
+if __name__ == "__main__":
+    day = Day(2024, 13)
+    day.run(verbose=True)

inputs/input13_test

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+Button A: X+94, Y+34
+Button B: X+22, Y+67
+Prize: X=8400, Y=5400
+
+Button A: X+26, Y+66
+Button B: X+67, Y+21
+Prize: X=12748, Y=12176
+
+Button A: X+17, Y+86
+Button B: X+84, Y+37
+Prize: X=7870, Y=6450
+
+Button A: X+69, Y+23
+Button B: X+27, Y+71
+Prize: X=18641, Y=10279