Cycle detection: Difference between revisions

=={{header|11l}}==

{{trans|D}}

<lang 11l>F brent(f, x0)

Int cycle_length

V hare = x0

V power = 1

L

V tortoise = hare

L(i) 1..power

hare = f(hare)

I tortoise == hare

cycle_length = i

^L.break

power *= 2

hare = x0

L 1..cycle_length

hare = f(hare)

V cycle_start = 0

V tortoise = x0

L tortoise != hare

tortoise = f(tortoise)

hare = f(hare)

cycle_start++

print_result(x0, f, cycle_length, cycle_start)

F print_result(x0, f, len, start)

print(‘Cycle length = ’len)

print(‘Start index = ’start)

V i = x0

L 1..start

i = f(i)

V cycle = [0] * len

L 0.<len

cycle[L.index] = i

i = f(i)

print(‘Cycle: ’, end' ‘’)

print(cycle)

brent(i -> (i * i + 1) % 255, 3)</lang>

{{out}}

<pre>

Cycle length = 6

Start index = 2

Cycle: [101, 2, 5, 26, 167, 95]

</pre>