HDOJ 2665 Kth number

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

Problem Description

Give you a sequence and ask you the kth big number of a inteval.

 

Input

The first line is the number of the test cases. 
For each test case, the first line contain two integer n and m (n, m <= 100000), indicates the number of integers in the sequence and the number of the quaere. 
The second line contains n integers, describe the sequence. 
Each of following m lines contains three integers s, t, k. 
[s, t] indicates the interval and k indicates the kth big number in interval [s, t]

 

Output

For each test case, output m lines. Each line contains the kth big number.

 

Sample Input

1 10 1 1 4 2 3 5 6 7 8 9 0 1 3 2 

 

Sample Output

2

 

Source

HDU男生专场公开赛——赶在女生之前先过节（From WHU）

 

#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;}