conficker-domains

Your mission

Walk today's generated list against the registered one and find the first name still free.

today's brief

November 2008. Conficker spreads through a Windows flaw that already had a patch, and reaches somewhere between 9 and 15 million machines. Every day it generated a fresh list of domains to call home, so defenders had to register the names before the worm asked for them. It worked, mostly. Find the first name they missed.

See it in action

first_free({3,7,9,12}, 4, {1,7,12,0})

Expected result

Your checklist

For your own tracking. Tests grade your code.

gen holds g domain ids generated for today, all above 0, sorted from smallest to largest with no repeats.
taken holds the ids the defenders already registered, sorted the same way and ended by a 0.
Return the first id in gen that is not in taken.
Return -1 when every generated id is already registered.

More examples

first_free({7,9,12}, 3, {1,7,12,0})

Expected result

first_free({1,2}, 2, {1,2,0})

Expected result

-1

Constraints

Expected files

domains.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

conficker-domains

Your mission

Walk today's generated list against the registered one and find the first name still free.

today's brief

See it in action

first_free({3,7,9,12}, 4, {1,7,12,0})

Expected result

Your checklist

For your own tracking. Tests grade your code.

gen holds g domain ids generated for today, all above 0, sorted from smallest to largest with no repeats.
taken holds the ids the defenders already registered, sorted the same way and ended by a 0.
Return the first id in gen that is not in taken.
Return -1 when every generated id is already registered.

More examples

first_free({7,9,12}, 3, {1,7,12,0})

Expected result

first_free({1,2}, 2, {1,2,0})

Expected result

-1

Constraints

Expected files

domains.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions