Dear Contestant,
I'm going to have a party at my villa at Hali-Bula to celebrate my retirement from BCM. I wish I could invite all my co-workers, but imagine how an employee can enjoy a party when he finds his boss among the guests! So, I decide not to invite both an employee and his/her boss. The organizational hierarchy at BCM is such that nobody has more than one boss, and there is one and only one employee with no boss at all (the Big Boss)! Can I ask you to please write a program to determine the maximum number of guests so that no employee is invited when his/her boss is invited too? I've attached the list of employees and the organizational hierarchy of BCM.
Best,
--Brian Bennett
The input consists of multiple test cases. Each test case is started with a line containing an integer n (1 ≦ n ≦ 200), the number of BCM employees. The next line contains the name of the Big Boss only. Each of the following n-1 lines contains the name of an employee together with the name of his/her boss. All names are strings of at least one and at most 100 letters and are separated by blanks. The last line of each test case contains a single 0.
For each test case, write a single line containing a number indicating the maximum number of guests that can be invited according to the required condition.
6 Jason Jack Jason Joe Jack Jill Jason John Jack Jim Jill 2 Ming Cho Ming 0
4 1
將boss-employee的關係建成一顆tree以後
對每個node必須存兩個值
一是此node選進來情況下包含此node及其子樹所能選的最多人
一是此node不選進來情況下包含此node及其子樹所能選的最多人
而最後的解答去看root的這兩個值取最大即可
至於這兩個值跟其child node的值得關係可以自己想想看
判斷是否唯一解的方法也類似另外再記錄兩個值即可
Migrated from old NTUJ.
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