in reply to Spiraling integers

81 chars to recursively construct the 2d array (not including "

`sub f {}`"):The first argument is the dimension of the spiral.sub f { #234567890123456789012345678901234567890123456789012345678901234567890 +12345678901 my$x=my$i=pop;$x?([1..$x],map[(map$_+2*$x-1,reverse@$_),++$i],reverse +f($x-1)):() }

The recursive pattern is the following: An n x n spiral looks like this:## print "@$_\n" for f(5); 1 2 3 4 5 16 17 18 19 6 15 24 25 20 7 14 23 22 21 8 13 12 11 10 9

where the *** box is the (n-1) x (n-1) spiral, rotated 180 degrees and 2n-1 added to each component.+---------------+ | 1 2 3 ... n | | +-------+ n+1 | | | | . | | | *** | . | | | | . | | +-------+ 2n-1| +---------------+

**Update:** oops, moved a `reverse` to the right spot (didn't affect char count).

blokhead

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