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 sequenceUltra-QuickSort produces the output
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
60
#include <iostream> #include <cstdio> # include <cstring> # include<algorithm> using namespace std; typedef long long ll; const int maxn=500000+5; ll a[maxn],b[maxn]; ll tot; void merge(int l,int m,int r) // 两集合合并 { int i=l,j=m+1,h=l; while(i<=m&&j<=r) { if(a[i]<a[j]) { b[h++]=a[i]; i++; } else {b[h++]=a[j]; j++; tot+=m-i+1; } } while(i<=m) { b[h++]=a[i]; i++; } while(j<=r) { b[h++]=a[j]; j++; } for(i=l;i<=r;i++) //还原 数组。。。。 a[i]=b[i]; } void ermmge(int x,int y) { int m; if(x<y) { m=(x+y)/2; ermmge(x,m); //递归调用 ermmge(m+1,y); //拆成大小单个元素的集合 merge(x,m,y); } } int main() { int t; while(~scanf("%d",&t)&&t!=0) { tot=0; for(int i=1;i<=t;i++) scanf("%lld", &a[i]); ermmge(1,t); printf("%lld\n",tot); } }
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Ultra-QuickSort
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