day 25 simplify

i can't believe this is faster but it is (slightly)

day24/input

@@ -0,0 +1,22 @@
+#.######################################################################################################################################################
+#.v><><<>^^^<><<>.^v<>v^>v^v^^<..^v>^>^vv.>v^<<>^.v<vvv<.>><v>><^>><>^<><v<>>>><v>v<^<>^.v..v^vv<v<<vv.v>>v<>v.<..^<vv<^v^v.v>>v>><^v>^<.vv^^<<><<>v>><#
+#.vv<vv<>.v<<<<<>>vv<>^v^^<^<>><.<^>^<^>^<v<<<<v>v>><.><.^><>vv<^^><<<<>^<.<v^.vv^vv>v>^.<<<><v<.v.<><<v^^v>^^<^>>^.<v^v.v><<v^vv<<v>^v>><^^<^<v>^>><v<#
+#<v^>v^vv<><v><<^<>^<^vv>v>>^^><<<vv><v.v.^><<^><>v>^<^v<<^>v<vv><v<<^.vv^>>>.^v>v.><v>v<^<^^<><<>><<^^^>v<^>>^v>>vv.<>^<><<^v>><^.>v^v><<^^^^<v<>^v<v.#
+#<<^<vv^<^><>^><>^vv.v^v>><^^<>^<>>^><^.^^<.v...>^^.^<<v<vvv>>>v^..^v.v<^><>.>v^.vv<^^vv>vv^.^.vv<v>>^>v.^^^<v<>><vv^>>^^.v>.v^^<^>vvv^<<v^<v<^><^>v<>>#
+#<.<^>>^<v><^>^^.>>v^<v^vvv>>vv.v^<>^^>v<<vv^<>^v.<<<^>>>.^>vvv.^^^<^><<^><v>><^.^>vv^^vv.><<v<^<v^^^.>v>^>v.^^<<^^^>^><><<vv<.<>v>vv>><^^v>>vvv^<...<<#
+#><v.v>vv>^^^>>><v>^^v>^>>><vv^<^<^<<<>.<<.<.<..><><v.v^^.v..v^>>>^v><.^^><<>v^<^<>^>>.v^v.v.>v>^>>>v>>^>><^<.v.v<^<<<<<^^>^^^^>^^<v^>>v><>.<>v><>.>><>#
+#<><<.>^<>^^v<v>^><^>v^.>><vv^vv^<v<<>.>.>>.vv.v<.^<^<>>^><><^.v>>v^^v><>><<<vv<<>v><>^.>>^>v^^><^<v<<><vv^>>.<^<.^<^>vvv>^<.v<^<>.><.>>v<^>^v<<.^<v>^<#
+#<>.<v^>.^<<^v^.<<^>v^^vv<^><^<^>><v^^vvv<<vvvv>>^v><<>^>vvvvv^<<v^.>^<.<^>.^>^><v^<>>.<<^^vv>>>^>vv><vvv^v.>^vv><<<<>^v^^^.>.^>>^^v^v>v>vv^<<^vv^<>v<>#
+#<<>v>v>>v^^v><^<.vv<^>^^>.v^<.^^vv>.<>^<>v>^>vvv<vv^>v^><<<v>vv<..^v^v>v.v><^.<^>.v<v><v>v^>^<<<<<>^.v<^.<v.<<^>v^^^<^<<>v.<<^<<<<.<^><<<^<v<v>>v>.><>#
+#>>.>vvv<<..>^^vv^>.<.v..v^^>^v<<>>>vv.<v>vv^<vv^v><v^^.<<.><..><^><<>^<<><v<.<v.<^<^.^<^<<><><<^v^>.<<v^^>.^<...v.^<^^<><><>v^<><^>^>^v^.>^^>^.vv.<v^>#
+#>.<><v>v<v>v>^v^^v>.v^.v>v>.<>>>^vv<<v>>^>^.^<^vv.vvvv<<>v<^^.>v<^v<<^><^.^^v<>.v<vv><v<v>vvv>^^>v>..<<<v..>v..<^^^<v>^^<<vv<>>^^v^.vv<><^>>.^<<^>>v.>#
+#><v..vv^<v^<>>v<>..<^>v^^><.>vv^vv^<^^v<>vv<.vv^^<>^>>^v<^^<<>^vv>v><>v<^vvv^<>><>^^^v^<v.v^<<^^>>>>><^^>><^v>>vv^v><^>^<<^.v>vv>^.v^<vv^v>>>vv>v^v<^>#
+#...>><v.<v<>^.v.v..^>^<><vv^><<<vv^<vv.><^.vv>>><v^v^>^v>>v<.^<^^<v^<>v<^<><<<.^<<vv.<>>^v^^.v>.<v>^.^>v^.v><^<<>>>^.<<<^v<<<><^>.^.^v><>^>><vv<v.<.^>#
+#<^vv>>v>v<^><^^^<^>vv<>vv>^^^.><><^>v>><v.<>vv^^<^<<<v^<><v>v^v>^<><><><><>^^>><>..^^>v<...vv<^>><.vv<^<v><v<vv^.><>v^<>v.^>>>v<<^<<^vv.>^<.^<>^<v^^^>#
+#>>^vv^.<<.<.<>>vvv<<<..<v><^<>^><<>^.<<^^^<v^<<v.<vv<^<>>vv^>.v^v<^<>>vv<<^>>.v>.v>^^^vvv^v<^><v^><>><^<.>v^^^<vv^>^v<v^<vv><>..^><.>^^<^>>..^.v^<^<v>#
+#<<><^^><v^v<^^<vv>><v..>>>^><>>>v>v>v>v><>>^vv><>>v>>vvvv<<^><>v^>vv>^.>>v.^<v<^.>>>^^v>>><vvv>><.<v<^<v<^v<v<<vvv..^^<<^<.<><<<<^<>v<<<^^>.^v>^^v<^^<#
+#>v^^^<v>^^<v<<<vv><^v.v<v^^^vvv<<><><^^><^^>>>>>><^>^^.>vv>^><<<v<<<^vv.^^^<v>v<^^^^>.^^vv<^<.<v^<vv^^^>><..><^>v><<v>v>^v^>>^^>vv.v^^^>^^vv.<<v.^><<.#
+#<^v<<^^vvv.>v>v>.v><v<^^>^>^>^^v>v^vv^<.^.>>>>>v<>.<<.<^<<vvv..<^>^><^>^<^<<>><^>v<v^v>^v^^^>>>>v>^>>^<v..><.>>^^><^<^.<v^>^.v>^^vv^v.<>>>>.v.<<>^^vv>#
+#<v^v.>.>^v>^<v.<^<^>v^>^^.>.>v<>>>^>vv<>v<>^>v^<<^<.<<^>v^<><>><^^<^^v<>>vv<<.<>v>.>^^^>><^^<^vv.><v<.<<^^>^>><>v><^vv.>v^v^v..<vvv..<<v<v^<<v>^<^>><<#
+#<^v<v^^v^>^<>v^<^<>>..>><>v<.^<.>v.>^v.>>^^<^v>>v^.v>^><>>vv.<<<>v>^.>v>..<<<v.<v^<>^>^<>v<^<v<><^>^v><.<<^^^<^.<<<^.^v^^.>^.<<vv>^v><<>^<^v^^>^v><<^>#
+######################################################################################################################################################.#

day24/sample

@@ -0,0 +1,6 @@
+#.######
+#>>.<^<#
+#.<..<<#
+#>v.><>#
+#<^v^^>#
+######.#

day24/sol.py

@@ -0,0 +1,135 @@
+data = []
+for line in open("input"):
+    data.append(line.strip())
+
+import sys, os; sys.path.append(os.path.join(os.path.dirname(__file__), "../lib"))
+import astar
+
+
+#print(*data, sep="\n")
+
+def show(t):
+    H = len(data)-2
+    for y in range(len(data)):
+        s = []
+        W = len(data[y])-2
+        for x in range(len(data[y])):
+            c = data[y][x]
+            if c == '#':
+                s.append(c)
+            else:
+                bliz = []
+                u = 1 + ((x - t)-1)%W
+                if data[y][u] == '>':
+                    bliz.append('>')
+
+                u = 1 + ((x + t)-1)%W
+                if data[y][u] == '<':
+                    bliz.append('<')
+
+                v = 1 + ((y - t)-1)%H
+                if data[v][x] == 'v':
+                    bliz.append('v')
+
+                v = 1 + ((y + t)-1)%H
+                if data[v][x] == '^':
+                    bliz.append('^')
+
+                if len(bliz) == 0:
+                    s.append('.')
+                elif len(bliz) == 1:
+                    s.append(bliz[0])
+                elif len(bliz) < 10:
+                    s.append(str(len(bliz)))
+                else:
+                    s.append('*')
+            
+        print(''.join(s))
+
+def blocked(x,y,t):
+    if not 0 <= y < len(data):
+        return True
+    if not 0 <= x < len(data[y]):
+        return True
+    if data[y][x] == '#':
+        return True
+
+    H = len(data)-2
+    W = len(data[y])-2
+
+    u = 1 + ((x - t)-1)%W
+    if data[y][u] == '>':
+        return True
+
+    u = 1 + ((x + t)-1)%W
+    if data[y][u] == '<':
+        return True
+
+    v = 1 + ((y - t)-1)%H
+    if data[v][x] == 'v':
+        return True
+
+    v = 1 + ((y + t)-1)%H
+    if data[v][x] == '^':
+        return True
+
+    return False
+
+start = (data[0].index('.'), 0)
+end = (data[-1].index('.'), len(data)-1)
+leg_distance = abs(start[0] - end[0]) + abs(start[1] - end[1])
+
+def is_goal(node, goal=end):
+    x, y, t = node
+    return (x,y) == goal
+
+def heuristic(node, goal=end):
+    x, y, t = node
+    return abs(goal[0] - x) + abs(goal[1] - y)
+
+def neighbors(node):
+    x, y, t = node
+    n = []
+    def check(dx,dy):
+        if not blocked(x+dx,y+dy,t+1):
+            n.append((1, (x+dx, y+dy, t+1)))
+    check(+1,0)
+    check(0,+1)
+    check(-1,0)
+    check(0,-1)
+    check(0,0)
+    return n
+
+show(0)
+show(1)
+#show((len(data)-2)*(len(data[0])-2))
+
+from functools import partial
+import time
+t0 = time.time()
+
+# part 1
+d1 = astar.search(start+(0,), is_goal, neighbors, heuristic)[0]
+
+t1 = time.time()
+
+# part 2
+# we can always take the best path for each leg,
+# rather than trying to compute it over the whole trip.
+# suppose there is a better overall path B = d1' + d2 + d3
+# with d1' > d1. we can "sync up" with this path by simply
+# waiting at the end square for d1'-d1 steps at the beginning
+# of the next leg. (A* will check this possibility for us.)
+# (the start and end squares are never blocked by blizzards.)
+# therefore even if we can complete later legs faster by
+# starting later, there is no downside to taking the shortest
+# path for all the previous legs.
+is_start = partial(is_goal, goal=start)
+heuristic2 = partial(heuristic, goal=start)
+d2 = astar.search(end+(d1,),      is_start, neighbors, heuristic2)[0]
+d3 = astar.search(start+(d1+d2,), is_goal, neighbors, heuristic)[0]
+
+t2 = time.time()
+
+print("part 1", d1, t1 - t0)
+print("part 2", d1+d2+d3, t2 - t0, "(%+f)"%(t2-t1))

day25/input

@@ -0,0 +1,125 @@
+2-=0102020-02
+1-02202=-1=-2==
+1==00-101-=0-
+211012=12222
+112-20
+11==0020-=20-=0=12=
+122-22110
+1==00-1201112==--=
+1-10==11=
+10=0=110-2
+1111=000=2001=211=
+22-21===0=-
+2=022
+11=-0100===
+10=10--==-0
+12=01-1
+12-01--20121-2-=0-1
+22-222--022-0-=01-
+12-1
+2-=2=02-1=
+2210
+1=2=0211
+10=01=001-01
+2
+201=-1
+11---10
+1=-0=
+1=-021
+1-2=02012111=01=-100
+1101=20=
+20-1-
+2-1020---
+2=121=0=10=
+1022-22211112=-1
+2-1-
+210--==00
+12=1122-10
+1=2222=2-=21=0
+1=021=
+1=10-1201
+1=1
+1-=-==0201-=1=0
+22=2=211-0-1=2=1
+1=21-=002111
+102112=10021
+1===-111-=2001122
+10--
+1-
+1-2-2
+11-1-1-02-
+1=20--=1=0101-1001
+12012-
+1220-1--00
+1=2=1-
+12-0=2022=0100-1
+12=2-=-=221==2=
+2-2-
+1=-1-01-0=
+12---2=
+1=1=1102-==010
+10-=--200=
+1=2212=-
+12-121=-
+1===0-=20-=
+1=2020-01---112=1-
+101=00111=20=
+1=2=01=1-2==0-
+2=-100---00
+1==1=01--===0-10-
+1==-=0-20
+1=2011121=10--2
+2-=0-01-=--12102=
+200
+2==22=0002-210
+102
+1-22221
+20==00
+1-22--2-0=10=11-1
+1=12=2
+1=-12-=
+10-020-100=0=
+1-11111
+1=02-002220
+20==0120210--1
+100-121=2-2-=00=
+21
+11=-=-
+2-=1100=10102-
+112--0-2=1--=2=
+1-1==100
+1--02-0=1-
+1102-
+1-2-21-
+22=1=-000=210-12
+1=112-12-
+1====120==0
+20=2=22=22=2-=2=
+1=21201=
+2202202-20
+1=-2=-==--200101
+12010
+1--22=2--02
+102==-
+2-==1-10
+12-==12-2
+22=-11110=2-211
+1-0
+1=02=20-1=--
+1-20
+1102---10
+11=2-==2=1-
+2=2-
+2=10=2==221=01
+1--==-1==
+1011-111
+1-2-=---012-21
+1=-==0
+1=0011=11112102=
+10-0-=202
+2-----12=
+1=-2221020=01-10
+12-2201==
+1-102
+22-100=0-===
+100=0-0

day25/sample

@@ -0,0 +1,13 @@
+1=-0-2
+12111
+2=0=
+21
+2=01
+111
+20012
+112
+1=-1=
+1-12
+12
+1=
+122

day25/sol.py

@@ -0,0 +1,36 @@
+def eval(num):
+    digits = ["=-012".index(c)-2 for c in num]
+    n = 0
+    for x in digits:
+        n = n*5 + x
+    return n
+
+def tosnafu(n):
+    orig = n
+    digits = []
+    carry = 0
+    while n != 0:
+        n, d = divmod(n, 5)
+        carry, d = divmod(d+carry, 5)
+        if d > 2:
+            carry += 1
+            d -= 5
+        digits.append(d)
+    if carry:
+        digits.append(carry)
+    digits.reverse()
+
+    snafu = "".join("=-012"[d+2] for d in digits)
+    #print(n, digits, snafu)
+    assert eval(snafu) == orig
+    return snafu
+
+t = 0
+for line in open("input"):
+    n = eval(line.strip())
+    print(n)
+    t += n
+
+print(t)
+print(tosnafu(t))
+