• [E] Course Scheduling

  • 时间限制: 1000 ms 内存限制: 65535 K
  • 问题描述
  • It is a difficult job to schedule all of the courses in a university to satisfy students' choices with a minimum of conflicts. The task is made all the more difficult when some students don't pre-enroll, or pre-enroll multiple times because they forget that they already did it.
  • 输入
  • The first line of input contains an integer 0 < n <= 100000, the number of student course requests. Each of the next n lines contains three strings separated by spaces: a student's first and last name, and the course that the student wishes to take. You may assume that each name is a string of at least one and at most 20 upper-case letters, and that a course is a string of at least one and at most 10 upper-case letters and digits. If a student requests a given course more than once, only the first such request should be considered. You may assume that no two students have both their first and last names the same.
  • 输出
  • For each requested course, output a line containing the course, a space, and the number of students who requested the course. Output the courses sorted in lexicographical order (with digits sorted before letters).
  • 样例输入
  • 1
    PINK TIE CS241
    
  • 样例输出
  • CS241 1
    
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  • 来源
  • 0 0
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