
ZOJ Problem Set  1340
Compute the fraction of the solardisc area that is visible at specified times after the onset of sunrise. This is a twobody problem; there is a single planet and a single star. Assume a perfectly spherical planet with a radius of 3950 miles. Ignore any possible atmospheric effects on the results to be determined. At a distance of 92,900,000 miles from the planet's center is an illuminating class four star. For the determinations to be made in this problem, ignore anyphenomena arising from the orbital motion of the planet about the star and consider the illuminating star to be a planar disc. The plane in which the disc lies is perpendicular to the line between the planet center and the solar disc center. The solar disc has a radius of 432,000 miles.
Assume the planet rotates uniformly, making one full rotation in precisely 24 hours. The sun is centered directly over the planet's equator during the entire revolution of the planet. Let time be measured from when the first solar rays of the morning reach a given reference point on the equator. For each time value giveninthe input data stream, compute the fraction of the solar disc area that is illuminating this reference point on the equator.
Process the input data stream until the endoffile is encountered.
0.0
0.000 Source: East Central North America 1995 