Here is my solution to the Knights challenge. It is in simple J.
The challenge is a more complex version of a Nice Knight APL puzzle that I
wrote in about 1975. I still think in a loopy fashion. The script is
attached.
knights ''
------------------------T--------┐
│11 12 13 14 15 16 17 18│W is 22 │
│21 22 23 24 25 26 27 28│B is 77 │
│31 32 33 34 35 36 37 38│W is 43 │
│41 42 43 44 45 46 47 48│B is 58 │
│51 52 53 54 55 56 57 58│W is 51 │
│61 62 63 64 65 66 67 68│B is 46 │
│71 72 73 74 75 76 77 78│W is 32 │
│81 82 83 84 85 86 87 88│B is 27 │
│ │W is 51 │
│ │B is 35 │
│ │W is 43 │
│ │B is 43 │
│ │10 moves│
L-----------------------+---------
Kip Murray made a big improvement over my control structures, so this is a
better way to do what I did.
]CB=: (10*1+i.8)+/1+i.8
]M=:_21 _19 _12 _8 8 12 19 21
]((22+M)e.,CB)#22+M
]((77+M)e.,CB)#77+M
n=: 13 :'((y+M)e.,CB)#y+M'
]n 22
]n 77
r=: 13 :'(?#n y){n y'
rm=: 13 :'r y'
rm 54
knights=: 3 : 0
AM=:('W is ',":W=:22),:'B is ',":B=:77
T =: ? 2
while. -.W=B do.
if. T do. AM=:AM,'W is ',":W=:rm W
else. AM=:AM,'B is ',":B=:rm B end.
T =: -.T
end.
CB;AM,(":_2+{.$AM),' moves'
)
knights ''
I am really looking for ways to write single sentences to achieve the final
result. In my next post from Raul Miller, I'll show what I mean.
Linda
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