Merge branch 'master' of git.martlubbers.net:aoc20

diff --cc 8/one.icl
index 6b4fde3,0000000..4365516
mode 100644,000000..100644
--- 1/8/one.icl
--- /dev/null
+++ b/8/one.icl
@@@ -1,43 -1,0 +1,41 @@@
- two = hd o filter snd o map interpret o nopjump 0
- 
- nopjump :: Int {Instr} -> [{Instr}]
- nopjump pc is
-       | pc == size is = []
-       = case is.[pc] of
-               Nop i = [update {i\\i<-:is} pc (Jmp i):nopjump (pc+1) is]
-               Jmp i = [update {i\\i<-:is} pc (Nop i):nopjump (pc+1) is]
-               _ = nopjump (pc+1) is
 +module one
 +
 +import StdEnv
 +
 +read :: *File -> [Instr]
 +read f
 +      # (l, f) = freadline f
 +      | l.[size l - 1] <> '\n' = []
 +      = [toInstr [c\\c<-:l | c <> '\n']:read f]
 +where
 +      toInstr ['nop ':rs] = Nop (toInt (toString rs))
 +      toInstr ['acc ':rs] = Acc (toInt (toString rs))
 +      toInstr ['jmp ':rs] = Jmp (toInt (toString rs))
 +
 +:: Instr = Nop Int | Acc Int | Jmp Int
 +
 +Start w
 +      # (io, w) = stdio w
 +      # instr = read io
 +      # instr = {c\\c<-instr}
 +      = (one instr, two instr)
 +
 +one = fst o interpret
-               | pc >= size instr = (acc, True)
-               | isMember pc vis = (acc, False)
++two is = [ acc \\i<-:is & pc<-[0..]
++      , let (acc, t) = interpret (update {i\\i<-:is} pc (swapnop i))
++      | t]
++where
++      swapnop (Nop i) = Jmp i
++      swapnop (Jmp i) = Nop i
++      swapnop i = i
 +
 +interpret :: {Instr} -> (Int, Bool)
 +interpret instr = int [] 0 0
 +where
 +      int vis pc acc
++              | pc >= size instr = (acc, True) // terminated
++              | isMember pc vis = (acc, False) // inf loop
 +              = case instr.[pc] of
 +                      Nop _ = int [pc:vis] (1 + pc) acc
 +                      Acc i = int [pc:vis] (1 + pc) (i + acc)
 +                      Jmp i = int [pc:vis] (i + pc) acc