patriot

Your mission

From the uptime in hours, compute the accumulated clock drift and return whether the tracking gate has slipped too far.

today's brief

February 25, 1991, Dhahran. A Patriot battery tracks an incoming Scud but never fires, and the missile hits a barracks, killing 28 American soldiers. The system counted time in tenths of a second, and one tenth cannot be stored exactly in its arithmetic, so a sliver of error piled up with every tick. After a hundred hours running without a reboot the clock had drifted about a third of a second, enough to swing the radar's search window hundreds of meters off. The grim workaround was to reboot often. Compute the drift and tell whether the intercept still lands.

See it in action

gate_slips(8)

Expected result

Your checklist

For your own tracking. Tests grade your code.

You get uptime_hours, the hours since the last reboot (non-negative).
Drift in milliseconds is uptime_hours * 343 / 100 (integer division).
The Scud moves 1676 meters per second, so the gate error in meters is drift_ms * 1676 / 1000 (integer division, applied to the drift you just computed).
Return 1 if the gate error is more than 500 meters (the intercept fails), 0 otherwise.

More examples

gate_slips(100)

Expected result

gate_slips(50)

Expected result

Constraints

Expected files

drift.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

patriot

Your mission

From the uptime in hours, compute the accumulated clock drift and return whether the tracking gate has slipped too far.

today's brief

See it in action

gate_slips(8)

Expected result

Your checklist

For your own tracking. Tests grade your code.

You get uptime_hours, the hours since the last reboot (non-negative).
Drift in milliseconds is uptime_hours * 343 / 100 (integer division).
The Scud moves 1676 meters per second, so the gate error in meters is drift_ms * 1676 / 1000 (integer division, applied to the drift you just computed).
Return 1 if the gate error is more than 500 meters (the intercept fails), 0 otherwise.

More examples

gate_slips(100)

Expected result

gate_slips(50)

Expected result

Constraints

Expected files

drift.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions