Set right-adjacent bits: Difference between revisions

=={{header|J}}==

Implementation:

<lang J>smearright=: {{ +./ (-i.1+x) |.!.0"0 1/ y }}</lang>

Here, we use J's bit array structure, so <tt>e</tt> is implicit in the length of the list.

Task examples:

<lang J>b=: '1'&= :.(' '-.~":)

task=: {{y,:x&smearright&.:b y}}

0 task '010000000000100000000010000000010000000100000010000010000100010010'

010000000000100000000010000000010000000100000010000010000100010010

010000000000100000000010000000010000000100000010000010000100010010

1 task '010000000000100000000010000000010000000100000010000010000100010010'

010000000000100000000010000000010000000100000010000010000100010010

011000000000110000000011000000011000000110000011000011000110011011

2 task '010000000000100000000010000000010000000100000010000010000100010010'

010000000000100000000010000000010000000100000010000010000100010010

011100000000111000000011100000011100000111000011100011100111011111

3 task '010000000000100000000010000000010000000100000010000010000100010010'

010000000000100000000010000000010000000100000010000010000100010010

011110000000111100000011110000011110000111100011110011110111111111</lang>

<code>b</code> converts from character list to bit list (and its obverse converts back to character list, for easy viewing).

<code>task</code> uses b on the right argument to <code>smearright</code> and its obverse on the result, which it provides with the original value (again, for easy viewing).