标签： 算法

未名湖附近共有N个大小湖泊L1, L2, …, Ln(其中包括未名湖)，每个湖泊Li里住着一只青蛙Fi(1 ≤ i ≤ N)。如果湖泊Li和Lj之间有水路相连，则青蛙Fi和Fj互称为邻居。现在已知每只青蛙的邻居数目x1, x2, …, xn，请你给出每两个湖泊之间的相连关系。

Due to recent rains, water has pooled in various places in Farmer John’s field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer John would like to figure out how many ponds have formed in his field. A pond is a connected set of squares with water in them, where a square is considered adjacent to all eight of its neighbors.
Given a diagram of Farmer John's field, determine how many ponds he has.

The stores manager has sorted all kinds of goods in an alphabetical order of their labels. All the kinds having labels starting with the same letter are stored in the same warehouse (i.e. in the same building) labelled with this letter. During the day the stores manager receives and books the orders of goods which are to be delivered from the store. Each order requires only one kind of goods. The stores manager processes the requests in the order of their booking.

朋友叫我打的，打完来写一下题解吧，题目质量方面，虽然大部分都不是原创题，但作为新生赛还算可以吧，推荐学完基础算法的可以来尝试一下。

An accutron shows time with four digits, from 0000 to 2359. Every digit is represented by 3*3 characters, including ‘|’s, ‘_’s and blanks. When the LCD screen works well, the digits look like the following:

工厂机器安排(贪心)

Today the company has m tasks to complete. The ith task need xi minutes to complete. Meanwhile, this task has a difficulty level yi. The machine whose level below this task’s level yi cannot complete this task. If the company completes this task, they will get (500xi+2yi) dollars.

The company has n machines. Each machine has a maximum working time and a level. If the time for the task is more than the maximum working time of the machine, the machine can not complete this task. Each machine can only complete a task one day. Each task can only be completed by one machine.

The company hopes to maximize the number of the tasks which they can complete today. If there are multiple solutions, they hopes to make the money maximum.

批处理作业调度是要从 n 个作业的所有排列中找出有最小完成时间和的作业调度，所以批处理调度问题的解空间是一棵排列树。按照回溯法搜索排列树的算法框架，设开始时x = [1, .., n]是所给的 n 个作业，则相应的排列树由所有排列构成。