解题报告

题意：

工厂有m台机器，须要做n个任务。对于一个任务i。你须要花费一个机器Pi天，并且，開始做这个任务的时间要>=Si，完毕这个任务的时间<=Ei。

对于一个任务，仅仅能由一个机器来完毕。一个机器同一时间仅仅能做一个任务。

可是，一个任务能够分成几段不连续的时间来完毕。问，是否能做完所有任务。

思路：

网络流在于建模，这题建模方式是：

把每一天和每一个任务看做点。由源点到每一任务。建容量为pi的边（表示任务须要多少天完毕）。

每一个任务到每一天，若是能够在这天做任务，建一条容量为1的边。最后。把每天到汇点再建一条边容量m（表示每台机器最多工作m个任务）。

#include 

Task Schedule

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 3311    Accepted Submission(s): 1154

Problem Description

Our geometry princess XMM has stoped her study in computational geometry to concentrate on her newly opened factory. Her factory has introduced M new machines in order to process the coming N tasks. For the i-th task, the factory has to start processing it at or after day Si, process it for Pi days, and finish the task before or at day Ei. A machine can only work on one task at a time, and each task can be processed by at most one machine at a time. However, a task can be interrupted and processed on different machines on different days. 

Now she wonders whether he has a feasible schedule to finish all the tasks in time. She turns to you for help.

 

Input

On the first line comes an integer T(T<=20), indicating the number of test cases.

You are given two integer N(N<=500) and M(M<=200) on the first line of each test case. Then on each of next N lines are three integers Pi, Si and Ei (1<=Pi, Si, Ei<=500), which have the meaning described in the description. It is guaranteed that in a feasible schedule every task that can be finished will be done before or at its end day.

 

Output

For each test case, print “Case x: ” first, where x is the case number. If there exists a feasible schedule to finish all the tasks, print “Yes”, otherwise print “No”.

Print a blank line after each test case.

 

Sample Input

2 4 3 1 3 5 1 1 4 2 3 7 3 5 9 2 2 2 1 3 1 2 2

 

Sample Output

Case 1: Yes Case 2: Yes

 

Author

allenlowesy

 

Source