17!

17/17.py

@@ -0,0 +1,90 @@
+from typing import Optional
+
+target_t = tuple[tuple[int, int], tuple[int, int]]
+
+START = (0, 0)
+
+
+class Nope(Exception):
+    pass
+
+
+def step_y(y: int) -> int:
+    return y - 1
+
+
+def step_x(x: int) -> int:
+    if x == 0:
+        return 0
+    elif x > 0:
+        return x - 1
+    else:
+        return x + 1
+
+
+def pos_in_target(x: int, y: int, target: target_t) -> bool:
+    if x > target[0][1] or y < target[1][0]:
+        raise Nope
+
+    if x < target[0][0] or y > target[1][1]:
+        return False
+
+    return True
+
+
+def brute_force(target: target_t):
+    best_y = 0
+
+    values_found = 0
+
+    for x0 in range(1, 200):
+        for y0 in range(-100, 100):
+            new_y = run_velocity(x0, y0, target)
+
+            if new_y is not None:
+                values_found += 1
+
+                if new_y > best_y:
+                    best_y = new_y
+
+    return best_y, values_found
+
+
+def run_velocity(dx: int, dy: int, target: target_t) -> Optional[int]:
+    x, y = START
+
+    max_y = 0
+
+    try:
+        while True:
+            x += dx
+            y += dy
+
+            max_y = max(y, max_y)
+
+            if pos_in_target(x, y, target):
+                return max_y
+
+            dx = step_x(dx)
+            dy = step_y(dy)
+
+    except Nope:
+        return None
+
+
+if __name__ == "__main__":
+    import re, sys
+
+    expression = r"target area: x=(-?\d+)\.\.(-?\d+), y=(-?\d+)\.\.(-?\d+)"
+    match = re.match(expression, sys.stdin.readline())
+
+    if not match:
+        exit(1)
+
+    numbers = [int(x) for x in match.groups()]
+    target: target_t = ((numbers[0], numbers[1]), (numbers[2], numbers[3]))
+
+    best, n = brute_force(target)
+
+    print("Part one:", best)
+    print("Part two:", n)