norad-tape

Your mission

Read the threat count off a frame, and refuse the ones that came from a training tape.

today's brief

November 9, 1979. A tape of a simulated Soviet attack gets loaded into the live system at Cheyenne Mountain, and the displays start showing missiles inbound. Ten interceptors went up. The president's airborne command post was readied, though he was not on it. Six minutes in, the raw radar and satellite feeds said nothing was coming and the alert was called off. Live or drill, the frames looked identical apart from one field.

See it in action

threat_count("L0042")

Expected result

Your checklist

For your own tracking. Tests grade your code.

msg is a null terminated frame. Its first character is the tag: L for a live report, T for a training tape.
The characters after the tag are the count, written as digits.
Return the count for a live report.
Return -1 for a training tape, for any other tag, and for a count above 9999.

More examples

threat_count("T0042")

Expected result

-1

threat_count("L0")

Expected result

Constraints

Expected files

frame.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

norad-tape

Your mission

Read the threat count off a frame, and refuse the ones that came from a training tape.

today's brief

See it in action

threat_count("L0042")

Expected result

Your checklist

For your own tracking. Tests grade your code.

msg is a null terminated frame. Its first character is the tag: L for a live report, T for a training tape.
The characters after the tag are the count, written as digits.
Return the count for a live report.
Return -1 for a training tape, for any other tag, and for a count above 9999.

More examples

threat_count("T0042")

Expected result

-1

threat_count("L0")

Expected result

Constraints

Expected files

frame.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions