静态区间第K小....划分树裸题

Kth number

Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 5341    Accepted Submission(s): 1733

1

10 1

1 4 2 3 5 6 7 8 9 0

1 3 2 

2

#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

using namespace std;

const int maxn=100100;

int tree[20][maxn];

int sorted[maxn];

int toleft[20][maxn];

void build(int l,int r,int dep)

{

    if(l==r) return ;

    int mid=(l+r)/2;

    int same=mid-l+1;

    for(int i=l;i<=r;i++)

        if(tree[dep][i]<sorted[mid]) same--;

    int lpos=l,rpos=mid+1;

    for(int i=l;i<=r;i++)

    {

        if(tree[dep][i]<sorted[mid])

            tree[dep+1][lpos++]=tree[dep][i];

        else if(tree[dep][i]==sorted[mid]&&same>0)

        {

            tree[dep+1][lpos++]=tree[dep][i];

            same--;

        }

        else tree[dep+1][rpos++]=tree[dep][i];

        toleft[dep][i]=toleft[dep][l-1]+lpos-l;

    }

    build(l,mid,dep+1);

    build(mid+1,r,dep+1);

}

int query(int L,int R,int l,int r,int dep,int k)

{

    if(l==r) return tree[dep][l];

    int mid=(L+R)/2;

    int cnt=toleft[dep][r]-toleft[dep][l-1];

    if(cnt>=k)

    {

        int newl=L+toleft[dep][l-1]-toleft[dep][L-1];

        int newr=newl+cnt-1;

        return query(L,mid,newl,newr,dep+1,k);

    }

    else

    {

        int newr=r+toleft[dep][R]-toleft[dep][r];

        int newl=newr-(r-l-cnt);

        return query(mid+1,R,newl,newr,dep+1,k-cnt);

    }

}

int main()

{

    int T_T,n,m;

    scanf("%d",&T_T);

    while(T_T--)

    {

        scanf("%d%d",&n,&m);

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

        {

            scanf("%d",sorted+i);

            tree[0][i]=sorted[i];

        }

        sort(sorted+1,sorted+1+n);

        build(1,n,0);

        int l,r,k;

        while(m--)

        {

            scanf("%d%d%d",&l,&r,&k);

            printf("%d\n",query(1,n,l,r,0,k));

        }

    }

    return 0;

}