13/02/23 16:32:26.69
>>181 J
spiral =: monad define
a=.1 1$1
n=.2
for. i.y do.
R=.|.n+i.{.$a
n=.n+#R
U=.|.n+i.1+#R
n=.n+#U
L=.n+i.#U
n=.n+#L
D=.n+i.1+#L
n=.n+#D
a=.D,~L,.U,a,.R
end.
a
)
spiral 1
5 4 3
6 1 2
7 8 9
13/02/23 16:32:26.69
>>181 J
spiral =: monad define
a=.1 1$1
n=.2
for. i.y do.
R=.|.n+i.{.$a
n=.n+#R
U=.|.n+i.1+#R
n=.n+#U
L=.n+i.#U
n=.n+#L
D=.n+i.1+#L
n=.n+#D
a=.D,~L,.U,a,.R
end.
a
)
spiral 1
5 4 3
6 1 2
7 8 9