21928_CleaningShifts

2022-5-16 18:20| 发布者: Hocassian| 查看: 41| 评论: 0|原作者: 肇庆学院ACM合集

摘要:
C:\Users\Administrator\Downloads\2019-10-12-10-14-4-89505967138300-Problem List-采集的数据-后羿采集器.html

Pro.ID

21928

Title

Cleaning Shifts

Title链接

http://10.20.2.8/oj/exercise/problem?problem_id=21928

AC

0

Submit

0

Ratio

-

时间&空间限制

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

    Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now require their barn to be immaculate. Farmer John, the most obliging of farmers, has no choice but hire some of the cows to clean the barn.

    Farmer John has N ( 1 ≤ N ≤ 10,000 ) cows who are willing to do some cleaning. Because dust falls continuously, the cows require that the farm be continuously cleaned during the workday, which runs from second number M to second number E during the day ( 0 ≤ ME ≤ 86,399 ). Note that the total number of seconds during which cleaning is to take place is E-M+1. During any given second M..E, at least one cow must be cleaning.

    Each cow has submitted a job application indicating her willingness to work during a certain interval T1..T2 (where MT1T2E ) for a certain salary of S (where 0 ≤ S ≤ 500,000 ). Note that a cow who indicated the interval 10..20 would work for 11 seconds, not 10. Farmer John must either accept or reject each individual application; he may NOT ask a cow to work only a fraction of the time it indicated and receive a corresponding fraction of the salary.

    Find a schedule in which every second of the workday is covered by at least one cow and which minimizes the total salary that goes to the cows.

    输入

    Line 1: Three space-separated integers: N, M, and E.

    Lines 2..N+1: Line i+1 describes cow i's schedule with three space-separated integers: T1, T1, and S.

    输出

    Description

    Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now require their barn to be immaculate. Farmer John, the most obliging of farmers, has no choice but hire some of the cows to clean the barn.

    Farmer John has N ( 1 ≤ N ≤ 10,000 ) cows who are willing to do some cleaning. Because dust falls continuously, the cows require that the farm be continuously cleaned during the workday, which runs from second number M to second number E during the day ( 0 ≤ ME ≤ 86,399 ). Note that the total number of seconds during which cleaning is to take place is E-M+1. During any given second M..E, at least one cow must be cleaning.

    Each cow has submitted a job application indicating her willingness to work during a certain interval T1..T2 (where MT1T2E ) for a certain salary of S (where 0 ≤ S ≤ 500,000 ). Note that a cow who indicated the interval 10..20 would work for 11 seconds, not 10. Farmer John must either accept or reject each individual application; he may NOT ask a cow to work only a fraction of the time it indicated and receive a corresponding fraction of the salary.

    Find a schedule in which every second of the workday is covered by at least one cow and which minimizes the total salary that goes to the cows.

    Input

    Line 1: Three space-separated integers: N, M, and E.

    Lines 2..N+1: Line i+1 describes cow i's schedule with three space-separated integers: T1, T1, and S.

    Output

    Line 1: a single integer that is either the minimum total salary to get the barn cleaned or else -1 if it is impossible to clean the barn.

    Sample Input

    3 0 4
    0 2 3
    3 4 2
    0 0 1

    Sample Output

    5

    Hint

    Explanation of the sample:

    FJ has three cows, and the barn needs to be cleaned from second 0 to second 4. The first cow is willing to work during seconds 0, 1, and 2 for a total salary of 3, etc.

    Farmer John can hire the first two cows.

    Source

    样例输入

    3 0 4
    0 2 3
    3 4 2
    0 0 1

    样例输出

    5

    提示

    Explanation of the sample:

    FJ has three cows, and the barn needs to be cleaned from second 0 to second 4. The first cow is willing to work during seconds 0, 1, and 2 for a total salary of 3, etc.

    Farmer John can hire the first two cows.


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