solarwinds-log

Your mission

Copy a release log into out with each id that repeats the one before it dropped.

today's brief

December 2020. FireEye works out why its red team tools walked off and finds a backdoor inside a signed SolarWinds Orion update, planted in the build system itself. Around 18,000 customers installed it. It had been going out through the normal update feed since March, and nothing about it ever looked wrong. Collapse the release log so the repeats stop hiding the shape of it.

See it in action

collapse(out, {5,5,5,7,7,5}, 6)

Expected result

3: 5 7 5

Your checklist

For your own tracking. Tests grade your code.

builds holds n release ids in the order they were pushed, and out has room for n of them.
Write into out the same sequence with any id that repeats the one right before it left out.
Return how many ids were written. n can be 0.

More examples

collapse(out, {1,2,3}, 3)

Expected result

3: 1 2 3

collapse(out, {}, 0)

Expected result

0:

Constraints

Expected files

releases.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

solarwinds-log

Your mission

Copy a release log into out with each id that repeats the one before it dropped.

today's brief

See it in action

collapse(out, {5,5,5,7,7,5}, 6)

Expected result

3: 5 7 5

Your checklist

For your own tracking. Tests grade your code.

builds holds n release ids in the order they were pushed, and out has room for n of them.
Write into out the same sequence with any id that repeats the one right before it left out.
Return how many ids were written. n can be 0.

More examples

collapse(out, {1,2,3}, 3)

Expected result

3: 1 2 3

collapse(out, {}, 0)

Expected result

0:

Constraints

Expected files

releases.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions