epoch-brick

Your mission

Return whether the device survives: its local time must not fall before the 1970 epoch.

today's brief

February 2016. Word spreads that you can brick any 64-bit iPhone by setting its date to January 1, 1970. People try it as a prank and their phones never boot again, not even after a charge or a reset. The clock counts seconds from that exact epoch, and once a timezone offset pushed the value below zero, a service buried in iOS tripped over the negative time and hung forever on the boot screen. Catch the underflow before the counter slides back past 1970.

See it in action

survives(0, 0)

Expected result

Your checklist

For your own tracking. Tests grade your code.

You get days_from_epoch (whole days since Jan 1 1970, can be 0) and tz_offset_hours (a timezone shift that can be negative).
Local time in seconds is days_from_epoch * 86400 + tz_offset_hours * 3600.
Return 1 if that local time is zero or positive (the phone boots), 0 if it is negative (bricked).

More examples

survives(0, -5)

Expected result

survives(1, -5)

Expected result

Constraints

Expected files

clock.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

epoch-brick

Your mission

Return whether the device survives: its local time must not fall before the 1970 epoch.

today's brief

See it in action

survives(0, 0)

Expected result

Your checklist

For your own tracking. Tests grade your code.

You get days_from_epoch (whole days since Jan 1 1970, can be 0) and tz_offset_hours (a timezone shift that can be negative).
Local time in seconds is days_from_epoch * 86400 + tz_offset_hours * 3600.
Return 1 if that local time is zero or positive (the phone boots), 0 if it is negative (bricked).

More examples

survives(0, -5)

Expected result

survives(1, -5)

Expected result

Constraints

Expected files

clock.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions