百练2299：Ultra-QuickSort（归并排序求逆序对数）

题目来源：http://bailian.openjudge.cn/practice/2299/

2299:Ultra-QuickSort

总时间限制: 7000ms      内存限制: 65536kB

描述

In this problem, you have to analyze a particular sortingalgorithm. The algorithm processes a sequence of n distinct integers byswapping two adjacent sequence elements until the sequence is sorted inascending order. For the input sequence 

9 1 0 5 4 ,

Ultra-QuickSort produces the output 

0 1 4 5 9 .