摘要: 1~N中与N互质的数的个数成为欧拉函数,记为$\varphi \left ( N \right ) $ 根据容斥原理易得: $$\varphi \left ( N \right ) = N \times \prod_{质数p\mid N}^{}\left ( 1-\frac{1}{p} \right 阅读全文
posted @ 2021-11-19 11:11 _vv123 阅读(99) 评论(0) 推荐(0) 编辑