Ultra-QuickSort

Ultra-QuickSort

Time Limit: 7000MS Memory Limit: 65536KTotal Submissions: 57708 Accepted: 21325

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

59105431230

Sample Output

60

#include <iostream>using namespace std;long long  cnt;void merge(int array[],int left,int mid,int right)//排序+统计{    int* temp=new int[right-left+1];    int i,j,p;    for(i=left,j=mid+1,p=0;i<=mid&&j<=right;p++)    {        if(array[i]<=array[j])            temp[p]=array[i++];        else        {            temp[p]=array[j++];            cnt+=(mid-i+1);        }    }    while(i<=mid)        temp[p++]=array[i++];    while(j<=right)        temp[p++]=array[j++];    for(i=left,p=0;i<=right;i++)        array[i]=temp[p++];    delete temp;}void mergesort(int array[],int left,int right)//二分{    if(left!=right)    {        int mid=(left+right)/2;        mergesort(array,left,mid);        mergesort(array,mid+1,right);        merge(array,left,mid,right);    }}int main(){    int n,array[500005];    while(cin>>n)    {        if(n==0)            break;        for(int i=0;i<n;i++)            cin>>array[i];        cnt=0;        mergesort(array,0,n-1);        cout<<cnt<<endl;    }    return 0;}