date-line

Your mission

Fold a longitude back into range after a heading change carries it past the date line.

today's brief

February 11, 2007. Twelve F-22 Raptors leave Hawaii for Okinawa, and the moment they cross the international date line every onboard computer drops out. Navigation gone, most of the radios with it. Nobody was hurt. The pilots stayed glued to their tankers and followed them back by eye, and Lockheed had a patch out inside 48 hours. Teach the nav computer what happens at 180 degrees.

See it in action

fold_longitude(179, 1)

Expected result

-180

Your checklist

For your own tracking. Tests grade your code.

lon is a whole number of degrees, at least -180 and at most 179.
delta is the change in degrees. It can be negative, and it can be larger than a full turn.
Return lon plus delta, brought back into -180 up to 179.

More examples

fold_longitude(-180, -1)

Expected result

fold_longitude(0, 0)

Expected result

Constraints

Expected files

nav.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions

date-line

Your mission

Fold a longitude back into range after a heading change carries it past the date line.

today's brief

See it in action

fold_longitude(179, 1)

Expected result

-180

Your checklist

For your own tracking. Tests grade your code.

lon is a whole number of degrees, at least -180 and at most 179.
delta is the change in degrees. It can be negative, and it can be larger than a full turn.
Return lon plus delta, brought back into -180 up to 179.

More examples

fold_longitude(-180, -1)

Expected result

fold_longitude(0, 0)

Expected result

Constraints

Expected files

nav.c

Allowed functions

None. Write every helper yourself.

Back to compete

Solutions