day15: add shitty solutions

Author: tfaughnan

day15/1.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env pypy3
+
+import functools
+import re
+import sys
+
+ROW_Y = 2_000_000
+
+def taxidist(p1, p2):
+    return abs(p1[0] - p2[0]) + abs(p1[1] - p2[1])
+
+def main():
+    xranges = set()
+    for line in sys.stdin:
+        sx, sy, bx, by = map(int, re.findall(r'-?[0-9]+', line.strip()))
+        d = taxidist((sx, sy), (bx, by))
+        rowd = taxidist((sx, sy), (sx, ROW_Y))
+        if rowd <= d:
+            xlower = sx - (d - rowd)
+            xupper = sx + (d - rowd)
+            if bx == xlower:
+                xlower += 1
+            elif bx == xupper:
+                xupper -= 1
+            xranges.add((xlower, xupper))
+
+    # XXX: wasteful!
+    xs = functools.reduce(set.union, (set(range(l, u + 1))
+                                      for l, u in xranges))
+    print(len(xs))
+
+if __name__ == '__main__':
+    main()

day15/2.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env pypy3
+
+import functools
+import re
+import sys
+
+MIN = 0
+MAX = 4_000_000
+
+def taxidist(p1, p2):
+    return abs(p1[0] - p2[0]) + abs(p1[1] - p2[1])
+
+def outer_perimeter(s, r):
+    sx, sy = s
+    x = sx - r - 1
+    y = sy
+    while y > sy - r - 1:
+        yield (x, y)
+        x += 1
+        y -= 1
+    while y < sy:
+        yield (x, y)
+        x += 1
+        y += 1
+    while y < sy + r + 1:
+        yield (x, y)
+        x -= 1
+        y += 1
+    while y > sy:
+        yield (x, y)
+        x -= 1
+        y -= 1
+
+def contained(p, signals, ignore):
+    for s, r in signals:
+        if s == ignore:
+            continue
+        d = taxidist(s, p)
+        if d <= r:
+            return True
+    return False
+
+def find_beacon(signals, minimum, maximum):
+    for s1, r1 in signals:
+        for p in outer_perimeter(s1, r1):
+            if ((not contained(p, signals, s1)) and
+                minimum <= p[0] <= maximum and
+                minimum <= p[1] <= maximum):
+                return p
+
+    raise AssertionError('bruh')
+
+def main():
+    signals = []
+    for line in sys.stdin:
+        sx, sy, bx, by = map(int, re.findall(r'-?[0-9]+', line.strip()))
+        signals.append(((sx, sy), taxidist((sx, sy), (bx, by))))
+
+    p = find_beacon(signals, MIN, MAX)
+    freq = p[0] * 4_000_000 + p[1]
+    print(freq)
+
+if __name__ == '__main__':
+    main()

day15/input.txt

@@ -0,0 +1,27 @@
+Sensor at x=2208586, y=2744871: closest beacon is at x=2094814, y=3380585
+Sensor at x=3937279, y=2452476: closest beacon is at x=3597034, y=2313095
+Sensor at x=3535638, y=3151860: closest beacon is at x=4098735, y=3373876
+Sensor at x=1867584, y=2125870: closest beacon is at x=2685670, y=2236965
+Sensor at x=2290971, y=1583182: closest beacon is at x=2685670, y=2236965
+Sensor at x=3137806, y=2216828: closest beacon is at x=3233556, y=2000000
+Sensor at x=3393352, y=331000: closest beacon is at x=3233556, y=2000000
+Sensor at x=1444302, y=821689: closest beacon is at x=1683873, y=-199301
+Sensor at x=1084667, y=3412239: closest beacon is at x=2094814, y=3380585
+Sensor at x=439341, y=3916996: closest beacon is at x=-290982, y=4102300
+Sensor at x=295460, y=2114590: closest beacon is at x=362644, y=370187
+Sensor at x=2212046, y=3819484: closest beacon is at x=2094814, y=3380585
+Sensor at x=3413280, y=3862465: closest beacon is at x=4098735, y=3373876
+Sensor at x=3744934, y=1572303: closest beacon is at x=3597034, y=2313095
+Sensor at x=3349047, y=2522469: closest beacon is at x=3597034, y=2313095
+Sensor at x=171415, y=591241: closest beacon is at x=362644, y=370187
+Sensor at x=3237499, y=2150414: closest beacon is at x=3233556, y=2000000
+Sensor at x=559077, y=454593: closest beacon is at x=362644, y=370187
+Sensor at x=3030733, y=2047512: closest beacon is at x=3233556, y=2000000
+Sensor at x=1667358, y=3956837: closest beacon is at x=2094814, y=3380585
+Sensor at x=1850337, y=98963: closest beacon is at x=1683873, y=-199301
+Sensor at x=2699546, y=3157824: closest beacon is at x=2094814, y=3380585
+Sensor at x=1113195, y=98130: closest beacon is at x=1683873, y=-199301
+Sensor at x=59337, y=246804: closest beacon is at x=362644, y=370187
+Sensor at x=566043, y=29068: closest beacon is at x=362644, y=370187
+Sensor at x=2831421, y=2581088: closest beacon is at x=2685670, y=2236965
+Sensor at x=597818, y=749461: closest beacon is at x=362644, y=370187

day15/sample.txt

@@ -0,0 +1,14 @@
+Sensor at x=2, y=18: closest beacon is at x=-2, y=15
+Sensor at x=9, y=16: closest beacon is at x=10, y=16
+Sensor at x=13, y=2: closest beacon is at x=15, y=3
+Sensor at x=12, y=14: closest beacon is at x=10, y=16
+Sensor at x=10, y=20: closest beacon is at x=10, y=16
+Sensor at x=14, y=17: closest beacon is at x=10, y=16
+Sensor at x=8, y=7: closest beacon is at x=2, y=10
+Sensor at x=2, y=0: closest beacon is at x=2, y=10
+Sensor at x=0, y=11: closest beacon is at x=2, y=10
+Sensor at x=20, y=14: closest beacon is at x=25, y=17
+Sensor at x=17, y=20: closest beacon is at x=21, y=22
+Sensor at x=16, y=7: closest beacon is at x=15, y=3
+Sensor at x=14, y=3: closest beacon is at x=15, y=3
+Sensor at x=20, y=1: closest beacon is at x=15, y=3