POJ 2299 Ultra-QuickSort

最新推荐文章于 2022-12-15 12:59:42 发布

HQD因为有趣所以做题

最新推荐文章于 2022-12-15 12:59:42 发布

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分类专栏： ACM_数据结构文章标签： tree input integer merge sorting output

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Ultra-QuickSort

Time Limit: 7000MS		Memory Limit: 65536K
Total Submissions: 15420		Accepted: 5435

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

Sample Output

6
0

Source

Waterloo local 2005.02.05

合并排序写的程序

#include<stdio.h>

int a[500005],t[500005];

__int64 cnt;

void merge_sort(int x,int y)

{

if(y-x>1)

{

int m=x+(y-x)/2;

int p=x,q=m,i=x;

merge_sort(x,m);

merge_sort(m,y);

while(p<m||q<y)

{

if(q>=y||(p<m&&a[p]<=a[q])) t[i++]=a[p++];

else {t[i++]=a[q++];cnt+=m-p;}//要是是后面的数加到前面去，那么就产生了逆序数

}

for(i=x;i<y;i++) a[i]=t[i];

}

int main()

{

int n;

while(scanf("%d",&n)==1&&n)

{

for(int i=0;i<n;i++) scanf("%d",&a[i]);

cnt=0;

merge_sort(0,n);

printf("%I64d/n",cnt);

}

return 0;

}

两个正确的树状数组+离散化写的程序

#include<cstdio>

#include<algorithm>

#include<cstring>

using namespace std;

struct t

{

int num,id;

}a[500005];

int b[500005],n;//离散化后放重新排序的数组

__int64 tree[500005];

__int64 cnt;

bool cmp(t a,t b)

{

return a.num<b.num;

}

inline int Lowbit(int x)

{

return x&(-x);

}

void Update(int x)

{

for(int i=x;i<=n;i+=Lowbit(i))

tree[i]++;

}

__int64 Getsum(int x)

{

__int64 temp=0;

for(int i=x;i>0;i-=Lowbit(i))

temp+=tree[i];

return temp;

}

int main()

{

while((scanf("%d",&n),n)!=0)

{

cnt=0;

memset(tree,0,sizeof(tree));

memset(b,0,sizeof(b));

for(int i=1;i<=n;i++)

{

scanf("%d",&a[i].num);

//a[i].num=1000000000-a[i].num;

a[i].id=i;

}

sort(a+1,a+n+1,cmp);

b[a[1].id]=1;

for(int i=2;i<=n;i++) //离散化

{

if(a[a[i].id].num!=a[a[i-1].id].num)

b[a[i].id]=i;

else

b[a[i].id]=b[a[i-1].id];

}

/*for(int i=1;i<=n;i++)

{

cnt+=Getsum(b[i]);

Update(b[i]);

}*/

for(int i=1;i<=n;i++)

{

Update(b[i]);

cnt+=(Getsum(n)-Getsum(b[i]));

}

printf("%I64d/n",cnt);

}

return 0;

}

#include<cstdio>

#include<algorithm>

#include<cstring>

using namespace std;

struct t

{

int num,id;

}a[500005];

int b[500005],n;//离散化后放重新排序的数组

__int64 tree[500005];

__int64 cnt;

bool cmp(t a,t b)

{

return a.num<b.num;

}

inline int Lowbit(int x)

{

return x&(-x);

}

void Update(int x)

{

for(int i=x;i>0;i-=Lowbit(i))

tree[i]++;

}

__int64 Getsum(int x)

{

__int64 temp=0;

for(int i=x;i<=n;i+=Lowbit(i))

temp+=tree[i];

return temp;

}

int main()

{

while((scanf("%d",&n),n)!=0)

{

cnt=0;

memset(tree,0,sizeof(tree));

memset(b,0,sizeof(b));

for(int i=1;i<=n;i++)

{

scanf("%d",&a[i].num);

// a[i].num=1<<31-1-a[i].num;

a[i].id=i;

}

sort(a+1,a+n+1,cmp);

b[a[1].id]=1;

for(int i=2;i<=n;i++) //离散化

{

if(a[a[i].id].num!=a[a[i-1].id].num)

b[a[i].id]=i;

else

b[a[i].id]=b[a[i-1].id];

}

for(int i=1;i<=n;i++)

{

cnt+=Getsum(b[i]);

Update(b[i]);

}

/* for(int i=1;i<=n;i++)

{

Update(b[i]);

cnt+=(Getsum(n)-Getsum(b[i]));

}*/

printf("%I64d/n",cnt);

}

return 0;

}

错误的程序，还是不知道哪错了

#include<cstdio>

#include<algorithm>

#include<cstring>

using namespace std;

struct t

{

int num,id;

}a[500005];

int b[500005],n;//离散化后放重新排序的数组

__int64 tree[500005];

__int64 cnt;

bool cmp(t a,t b)

{

return a.num<b.num;

}

inline int Lowbit(int x)

{

return x&(-x);

}

void Update(int x)

{

for(int i=x;i<=n;i+=Lowbit(i))

tree[i]++;

}

__int64 Getsum(int x)

{

__int64 temp=0;

for(int i=x;i>0;i-=Lowbit(i))

temp+=tree[i];

return temp;

}

int main()

{

while((scanf("%d",&n),n)!=0)

{

cnt=0;

memset(tree,0,sizeof(tree));

memset(b,0,sizeof(b));

for(int i=1;i<=n;i++)

{

scanf("%d",&a[i].num);

a[i].num=1<<31-1-a[i].num;

a[i].id=i;

}

sort(a+1,a+n+1,cmp);

b[a[1].id]=1;

for(int i=2;i<=n;i++) //离散化

{

if(a[a[i].id].num!=a[a[i-1].id].num)

b[a[i].id]=i;

else

b[a[i].id]=b[a[i-1].id];

}

for(int i=1;i<=n;i++)

{

cnt+=Getsum(b[i]);

Update(b[i]);

}

/* for(int i=1;i<=n;i++)

{

Update(b[i]);

cnt+=(Getsum(n)-Getsum(b[i]));

}*/

printf("%I64d/n",cnt);

}

return 0;

}