bgp

Your mission

Return whether an address is still covered by an announced block.

today's brief

October 4, 2021. A routine audit command goes wrong and Facebook withdraws the BGP routes to its own network. Every address it owns just stops existing as far as the rest of the internet is concerned, and it stays that way for six hours. The engineers who could undo it could not badge into the building, because the door system needed the network too. Answer the question the routers kept asking: is this address still announced?

See it in action

reachable({100,500}, {10,5}, 2, 105)

Expected result

Your checklist

For your own tracking. Tests grade your code.

The table holds n announced blocks. Block i covers every address from base[i] up to base[i] + size[i] - 1.
Return 1 when at least one block covers addr, and 0 otherwise.
A block of size 0 covers nothing.

More examples

reachable({100,500}, {10,5}, 2, 110)

Expected result

reachable({}, {}, 0, 100)

Expected result

Constraints

Expected files

route.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

bgp

Your mission

Return whether an address is still covered by an announced block.

today's brief

See it in action

reachable({100,500}, {10,5}, 2, 105)

Expected result

Your checklist

For your own tracking. Tests grade your code.

The table holds n announced blocks. Block i covers every address from base[i] up to base[i] + size[i] - 1.
Return 1 when at least one block covers addr, and 0 otherwise.
A block of size 0 covers nothing.

More examples

reachable({100,500}, {10,5}, 2, 110)

Expected result

reachable({}, {}, 0, 100)

Expected result

Constraints

Expected files

route.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions