1347  Reverse Number
Time Limit : 1 Second
Memory Limit : 128 MB
Submission: 547
Solved: 116
 Description
 Given a nonnegative integer sequence A with length N, you can exchange two adjacent numbers each time. After K exchanging operations, what’s the minimum reverse number the sequence can achieve?
The reverse number of a sequence is the number of pairs (i, j) such that
i < j and Ai > Aj
 Input
 There are multiple cases.
For each case, first line contains two numbers: N, K
2<=N<=100000, 0 <= K < 2^60
Second line contains N nonnegative numbers, each of which not greater than 2^30
 Output
 Minimum reverse number you can get after K exchanging operations.
 sample input

3 1 3 2 1 5 2 5 1 4 3 2
 sample output

Case #1: 2 Case #2: 5
 hint
 source
 Liu Fei, HUST Campus 2009