摘要: [BZOJ2152]聪聪可可 题目大意: 一棵$n(n\le20000)$个点的带边权的树,求任选两个点使得路径上边权和是$3$的倍数的概率。 思路: 基础树形DP。 源代码: cpp include include include include inline int getint() { reg 阅读全文
posted @ 2018-07-30 14:58 skylee03 阅读(93) 评论(0) 推荐(0)