动态区间第k小 分块 O（nlogn*sqrt（nlogn））

代码：

#include<iostream>#include<string.h>#include<stdio.h>#include<algorithm>#include<cmath>using namespace std;int n,q;struct node{    int x,y;}a[100005];int b[100008];int L[8005],R[8005];int id[1000008];int k;int cmp(node xx,node yy){    return xx.x<yy.x;   }void pa(int x){    //cout<<x<<endl;    sort(a+L[x],a+R[x]+1,cmp);  }void add(int l,int r,int v){    int k=id[l];    for(int i=L[k];i<=R[k];i++)    if(a[i].y<=r&&a[i].y>=l) a[i].x+=v;    pa(k);}int suan(int l,int r,int x){    int ret=0;    int k=id[l];    for(int i=L[k];i<=R[k];i++)    if(a[i].y<=r&&a[i].y>=l&&a[i].x<=x) ret++;    return ret;     }int qu(int k,int x){    int ll=L[k],rr=R[k];    //  cout<<a[714].x<<endl;    while(ll<rr)    {    //  cout<<ll<<"   "<<rr<<endl;        int mid=(ll+rr+1)>>1;        if(a[mid].x+b[k]<=x) ll=mid; else rr=mid-1;    }    if(a[ll].x+b[k]>x) ll--;    return ll-L[k]+1;}int C(int l,int r,int x){    int ret=0;    //cout<<id[l]<<"  "<<id[r]<<endl;    if(id[l]==id[r]) return suan(l,r,x);    ret+=suan(l,R[id[l]],x);    ret+=suan(L[id[r]],r,x);//  cout<<ret<<endl;    for(int i=id[l]+1;i<id[r];i++)    ret+=qu(i,x);    return ret;}int main(){    int aa,bb,cc,dd;    scanf("%d",&n);    for(int i=1;i<=n;i++)    {        scanf("%d",&a[i].x);        a[i].y=i;    }     scanf("%d",&q);    int m=sqrt(n) ;    k=n/m;    if(k*m<n) k++;    for(int i=1;i<=n;i++)   id[i]=(i-1)/m+1;    for(int i=1;i<=k;i++)    {        L[i]=m*(i-1)+1;        R[i]=min(n,m*i);        pa(i);    }    for(int i=1;i<=q;i++)    {        scanf("%d%d%d%d",&dd,&aa,&bb,&cc);        if(dd==1)        {        //cout<<"Sb"<<endl;                if(id[aa]==id[bb]) add(aa,bb,cc);                else                 {                    add(aa,R[id[aa]],cc);                    add(L[id[bb]],bb,cc);                    for(int j=id[aa]+1;j<id[bb];j++) b[j]+=cc;                }        }        else         {                int ll=-5000000,rr=5000000;                while(ll<rr)                {                    int mid=(ll+rr)>>1;//cout<<ll<<"  "<<rr<<"       "<<mid<<endl;                    if(C(aa,bb,mid)>=cc) rr=mid; else ll=mid+1;                 }                printf("%d\n",ll);        }    }}