cogs 1345 [ZJOI2013] K大数查询

【分析】

整体二分…好像是在CDQ的基础上再加一个二分QAQ
cogs评测机好快…刷到Rank1了…然而这题在bzoj上过不了(为啥数据不一样啊)，洛谷上会被卡一个比较奇葩的点…懵逼脸

【代码】

//K大数查询 
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define ll long long
#define M(a) memset(a,sizeof a)
#define fo(i,j,k) for(i=j;i<=k;i++)
using namespace std;
const int mxn=50005;
bool vis[mxn];
int n,m,c1[mxn],c2[mxn],ans[mxn];
struct query {int opt,l,r,v,id;} a[mxn],tmp[mxn];
inline int lowbit(int x) {return x&-x;}
inline void add_(int *c,int x,int v)
{
    for(int i=x;i<=n;i+=lowbit(i))
      c[i]+=v;
}
inline void add(int l,int r,int v)
{
    add_(c1,v),add_(c1,r+1,-v);
    add_(c2,v*(l-1)),add_(c2,-v*r);
}
inline int getsum(int *c,int x)
{
    int S=0;
    for(int i=x;i>=1;i-=lowbit(i))
      S+=c[i];
    return S;
}
inline int get(int l,int r)
{
    int sum1=(l-1)*getsum(c1,l-1)-getsum(c2,l-1);
    int sum2=r*getsum(c1,r)-getsum(c2,r);
    return sum2-sum1;
}
inline void CDQ(int L,int R,int l,int r)
{
    int i,mid=l+r>>1,l1=L,l2=R;
    if(l==r)
    {
        fo(i,L,R) if(a[i].opt==2) ans[a[i].id]=l;
        return;
    }
    fo(i,R)
    {
        if(a[i].opt==1)
        {
            if(a[i].v<=mid) tmp[l1++]=a[i];
            else
            {
                add(a[i].l,a[i].r,1);
                tmp[l2--]=a[i];
            }
        }
        else
        {
            int cnt=get(a[i].l,a[i].r);
            if(a[i].v>cnt)
              a[i].v-=cnt,tmp[l1++]=a[i];
            else tmp[l2--]=a[i];
        }
    }
    reverse(tmp+l2+1,tmp+R+1);
    fo(i,R) a[i]=tmp[i];
    fo(i,R) if(a[i].opt==1 && a[i].v>mid) add(a[i].l,-1);
    CDQ(L,l1-1,mid),CDQ(l2+1,R,mid+1,r);
}
int main()
{
    freopen("zjoi13_sequence.in","r",stdin);
    freopen("zjoi13_sequence.out","w",stdout);
    int i,j;
    scanf("%d%d",&n,&m);
    fo(i,1,m)
    {
        scanf("%d%d%d%d",&a[i].opt,&a[i].l,&a[i].r,&a[i].v);
        if(a[i].opt==2) vis[i]=1;a[i].id=i;
    }
    CDQ(1,-n,n);
    fo(i,m) if(vis[i]) printf("%d\n",ans[i]);
    return 0;
}