摘要：
The French author Georges Perec (1936–1982) once wrote a book, La disparition, without the letter 'e'. He was a member of the Oulipo group. A quote fr 阅读全文
摘要：
There are n distinct points in the plane, given by their integer coordinates. Find the number of parallelograms whose vertices lie on these points. In 阅读全文
摘要：
链接：https://www.nowcoder.com/acm/contest/114/B来源：牛客网 题目描述 Ans = 0; For(inti = 1; i <= n; i++) For(int v = 0; v <= n; v++) Ans = (Ans + C(i, v) * C(i, v 阅读全文