Telefraud(电信诈骗) remains a common and persistent problem in our society. In some cases, unsuspecting victims lose their entire life savings. To stop this crime, you are supposed to write a program to detect those suspects from a huge amount of phone call records.
A person must be detected as a suspect if he/she makes more than K short phone calls to different people everyday, but no more than 20% of these people would call back. And more, if two suspects are calling each other, we say they might belong to the same gang. A makes a short phone call to B means that the total duration of the calls from A to B is no more than 5 minutes.
Each input file contains one test case. For each case, the first line gives 3 positive integers K (≤500, the threshold(阈值) of the amount of short phone calls), N (≤103, the number of different phone numbers), and M (≤105, the number of phone call records). Then M lines of one day's records are given, each in the format:
caller receiver duration
where caller
and receiver
are numbered from 1 to N, and duration
is no more than 1440 minutes in a day.
Print in each line all the detected suspects in a gang, in ascending order of their numbers. The gangs are printed in ascending order of their first members. The numbers in a line must be separated by exactly 1 space, and there must be no extra space at the beginning or the end of the line.
If no one is detected, output None
instead.
5 15 31
1 4 2
1 5 2
1 5 4
1 7 5
1 8 3
1 9 1
1 6 5
1 15 2
1 15 5
3 2 2
3 5 15
3 13 1
3 12 1
3 14 1
3 10 2
3 11 5
5 2 1
5 3 10
5 1 1
5 7 2
5 6 1
5 13 4
5 15 1
11 10 5
12 14 1
6 1 1
6 9 2
6 10 5
6 11 2
6 12 1
6 13 1
3 5
6
Note: In sample 1, although 1
had 9 records, but there were 7 distinct receivers, among which 5
and 15
both had conversations lasted more than 5 minutes in total. Hence 1
had made 5 short phone calls and didn't exceed the threshold 5, and therefore is not a suspect.
5 7 8
1 2 1
1 3 1
1 4 1
1 5 1
1 6 1
1 7 1
2 1 1
3 1 1
None
(1)输入时,记录每对打电话和接电话人的通话时长;
(2)二重循环遍历所有两人组合,如果两人之间的通话时间总和不超过5分钟,记为有效通话,同时如果反过来,这组接电话的人有回电话,即时间大于零,就记这组打电话的人被回了一次电话。
(3)从1到N遍历编号,如果有效通话次数大于k并且被回电话的次数不超过20%,则把这个人列为嫌疑人。
(4)嫌疑人个数为0则直接输出none
(5)并查集分帮派,二重循环遍历所有嫌疑人的两人组合,如果两个人互相打过电话,则merge。
(6)遍历所有嫌疑人,以嫌疑人并查集中的父节点作为下标,建立帮派结构体,记录每个帮派中嫌疑人的数量和编号。
(7)对每个帮派中的所有嫌疑人进行升序排序
(8)对帮派进行排序
(9)输出
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