HBC24882夹缝中求和,枚举,尺取法[USACO 2009 Ope G]Bovine Embroidery题解

不断提升技能，才能在职场中立于不败之地！全网最全C++题库，助您成为编程领域的佼佼者。

Bessie has taken up the detailed art of bovine embroidery. Cows embroider a cloth mounted in a circular hoop of integer radius d (1

Bessie has taken up the detailed art of bovine embroidery. Cows embroider a cloth mounted in a circular hoop of integer radius d (1 <= d <= 50,000). They sew N (2 <= N <= 50,000) threads, each in a straight line from one point on the edge of the hoop to another point on the edge of the hoop (no two embroidered points share a location on the hoop's edge). Being mathematically inclined, Bessie knows a formula of the form ax + by + c = 0 for each straight line piece of thread. Conveniently, a, b, and c are integers (-1,000,000 <= a <= 1,000,000; -1,000,000 <= b <= 1,000,000; -1,000,000 <= c <= 1,000,000). Even more conveniently, no two threads coincide exactly. Perhaps less conveniently, Bessie knows that her set of formula coefficients also includes a number of formulae for threads that do not appear to pass inside the hoop's circle. She regrets this greatly. The origin (0,0) is in the precise middle of the hoop, so all points on the hoop's edge are distance d from the origin. At least one of the coefficients a and b is non-zero for each thread's formula. Bovine embroidery is more highly regarded when the number of thread intersections is maximized. Help Bessie: count the number of pairs of threads that intersect on the cloth (i.e., within distance d of the origin). Note that if three threads happen to coincide at the same point, that would be three pairs of intersections. Four threads at the same point -> six pairs of intersections, etc.

想要在职场中立于不败之地？那就来试试全网最全C++题库，让您在练习中快速提升技能。

标签： HBC24882夹缝中求和 枚举 尺取法[USACO 2009 Ope G]Bovine Embroidery题解