1158 Telefraud Detection

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.

Input Specification:

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.

Output Specification:

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.

Sample Input 1:

Sample Output 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.

Sample Input 2:

Sample Output 2:

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