Ultra-QuickSort

Description

In this problem, you have to analyze a particular sorting algorithm. The algorithm processes a sequence of n distinct integers by swapping two adjacent sequence elements until the sequence is sorted in ascending order. For the input sequence
9 1 0 5 4 ,
Ultra-QuickSort produces the output
0 1 4 5 9 .
Your task is to determine how many swap operations Ultra-QuickSort needs to perform in order to sort a given input sequence.

Input

The input contains several test cases. Every test case begins with a line that contains a single integer n < 500,000 -- the length of the input sequence. Each of the the following n lines contains a single integer 0 ≤ a[i] ≤ 999,999,999, the i-th input sequence element. Input is terminated by a sequence of length n = 0. This sequence must not be processed.

Output

For every input sequence, your program prints a single line containing an integer number op, the minimum number of swap operations necessary to sort the given input sequence.

Sample Input

5
9
1
0
5
4
3
1
2
3
0

Sample Output

6

0

树状数组

#include
#include
#include
#include
#define lowbit(x) (x&(-x))
#define ls(x) (x<<1)//尽量宏定义吧，不太容易出错 
#define rs(x) (x<<1|1)
using namespace std;
typedef long long ll;
const int maxn=5e5+10;

struct node{
	int val,id;
	bool operator<(const node& b)const{
		return val0){
		ans+=tree[val];
		val-=lowbit(val);
	}
	return ans;
}

int main()
{
	while(scanf("%d",&n)&&n){
		for(int i=0;i