摘要: B - RGB Coloring 求ax + by = k (0<=x<=n && 0<=y<=n)的方案数,最后乘上C(n, x)*C(n,y) 代码: 阅读全文
posted @ 2018-06-06 14:55 Wisdom+.+ 阅读(281) 评论(0) 推荐(0)