摘要：Test for Job Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. Nowadays, It's hard to have 阅读全文

摘要：Delete 题目描述 给定一张n个点，m条边的带权有向无环图，同时给定起点S和终点T，一共有q个询问，每次询问删掉某个点和所有与它相连的边之后S到T的最短路，询问之间互相独立(即删除操作在询问结束之后会立即撤销)，如果删了那个点后不存在S到T的最短路，则输出-1。 输入描述: 第一行四个正整数表示 阅读全文

摘要：Telephone Lines 题目描述 Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay f 阅读全文

摘要：链接 题目描述 小雨所在的城市一共有 m 条地铁线，分别标号为 1 号线，2 号线，……，m 号线。整个城市一共有 n 个车 站，编号为 $1 \sim n$ 。其中坐 i 号线需要花费 \(a_i\) 的价格，每坐一站就需要多花费 \(b_i\) 的价格。i 号 线有 \(c_i\) 个车站，而且 阅读全文