题目 Source http://codeforces.com/contest/632/problem/E Description A thief made his way to a shop. As usual he has his lucky knapsack with him. The knapsack can contain k objects. There are n kind...
0. 前置芝士 基础群论 复数 \(\mathbb C = \mathbb R[x^2+1]\) 则有 \(i^2+1=(-i)^2+1=0\),\(i \in \mathbb C - \mathbb R\) \(i^0=1;i^1=i;i^2=-1;i^3=-i;i^x=i^{x \bmod 4}(x \in \mathbb Z)\) 定理 0.1(欧拉...