P2617 Dynamic Rankings 整体二分

  

带修的区间第k大

只要在修改操作之前将原数删除一下即可 (整体二分最外层是维护时间轴的!!!!! 操作过程中永远保证时间轴有序 )

// luogu-judger-enable-o2
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define repp(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
#define see(x) (cerr<<(#x)<<'='<<(x)<<endl)
#define inf 0x3f3f3f3f
#define CLR(A,v)  memset(A,v,sizeof A)
/////////////////////////////////////
const int N=1e6+10;
int n,m,t[N],k,ans[N],cnt,a[N],tot;
void add(int x,int v){for(;x<=N;x+=x&-x)t[x]+=v;}
int qsum(int x){int ans=0;for(;x;x-=x&-x)ans+=t[x];return ans;}
struct node{int l,r,k,op,id;}s[N],temp1[N],temp2[N];

void cdq(int l,int r,int L,int R)
{   
    if(L>R)return ;
    if(l==r)
    {
        rep(i,L,R)if(s[i].op==2)ans[s[i].id]=l;
        return ;
    }
    int mid=(l+r)>>1,cnt1=0,cnt2=0;
    rep(i,L,R)
    {
        if(s[i].op==1)
        {
            if(s[i].l<=mid)add(s[i].id,s[i].r),temp1[++cnt1]=s[i];
            else temp2[++cnt2]=s[i];
        }
        else 
        {
            int x=qsum(s[i].r)-qsum(s[i].l-1);
            if(s[i].k<=x)temp1[++cnt1]=s[i];
            else  s[i].k-=x,temp2[++cnt2]=s[i];
        }
    }
    rep(i,1,cnt1)if(temp1[i].op==1)add(temp1[i].id,-temp1[i].r);
    rep(i,1,cnt1)s[L-1+i]=temp1[i];
    rep(i,1,cnt2)s[L+cnt1-1+i]=temp2[i];
    cdq(l,mid,L,L+cnt1-1);
    cdq(mid+1,r,L+cnt1,R);
}
int main()
{
    cin>>n>>m;
    rep(i,1,n)
    cnt++,scanf("%d",&s[cnt].l),s[cnt].r=1,s[cnt].k=0,s[cnt].id=i,s[cnt].op=1,a[i]=s[cnt].l;
    rep(i,1,m)
    {
        int l,r,k;char ss[2];scanf("%s",ss);
        if(ss[0]=='Q')
        scanf("%d%d%d",&l,&r,&k),s[++cnt]=(node){l,r,k,2,++tot};
        else 
        scanf("%d%d",&l,&r),s[++cnt]=(node){a[l],-1,0,1,l},s[++cnt]=(node){a[l]=r,1,0,1,l};
    }
    cdq(-inf,inf,1,cnt);
    rep(i,1,tot)
    printf("%d
",ans[i]);
    return 0;
}
View Code
原文地址:https://www.cnblogs.com/bxd123/p/11468186.html