HDU 2665 Kth number

题目链接 : HDU2665

Kth number

Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3155    Accepted Submission(s): 1055

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）

 

 

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划分树模板题    不知道以后会不会用Splay再写一次

 

 

#include<cstdio>#include<cstring>#include<cmath>#include<cstdlib>#include<algorithm>#include<string>#include<vector>#include<map>#include<set>#include<queue>using namespace std;int tree[20][100005],left[20][100005];int num[100005];bool cmp(int a,int b){    return tree[1][a]<tree[1][b];}void build_tree(int l,int r,int dep){    if(l==r)return;    int mid=(l+r)>>1;    int lpos=l,rpos=mid+1;    for(int i=l;i<=r;i++)    {        if(tree[dep][i]>mid) tree[dep+1][rpos++]=tree[dep][i];        else tree[dep+1][lpos++]=tree[dep][i];        left[dep][i]=lpos-l;    }    build_tree(l,mid,dep+1);    build_tree(mid+1,r,dep+1);}int query(int lef,int rig,int l,int r,int dep,int k){    if(l==r) return tree[dep][l];    int mid=(lef+rig)>>1;    int cnt=left[dep][r]-((l!=lef)?left[dep][l-1]:0);    if(cnt<k)    {        int newl=left[dep][rig]+l-((l!=lef)?left[dep][l-1]:0);        int newr=newl+(r-l-cnt);        return query(mid+1,rig,newl,newr,dep+1,k-cnt);    }    else    {        int newl=lef+((l!=lef)?left[dep][l-1]:0);        int newr=newl+cnt-1;        return query(lef,mid,newl,newr,dep+1,k);    }}int main(){    int t;    scanf("%d",&t);    while(t--)    {        int n,m;        scanf("%d%d",&n,&m);        for(int i=1;i<=n;i++)            scanf("%d",&tree[1][i]),num[i]=i;        sort(num+1,num+n+1,cmp);        for(int i=1;i<=n;i++)            tree[0][num[i]]=i;        for(int i=1;i<=n;i++)            num[i]=tree[1][num[i]];        build_tree(1,n,0);        int l,r,k;        while(m--)        {            scanf("%d%d%d",&l,&r,&k);            printf("%d\n",num[query(1,n,l,r,0,k)]);        }    }    return 0;}