Submission #928999

#	Time	Username	Problem	Language	Result	Execution time	Memory
928999		Warinchai	Index (COCI21_index)	C++14	110 / 110	411 ms	136628 KiB

index

#include<bits/stdc++.h>
using namespace std;
int inf=1e9;
struct segtree{
    struct node{
        int sum;
        node *l,*r;
        node(int x=0){
            sum=x;
            l=r=NULL;
        }
    };
    typedef node* pnode;
    pnode rt[200005];
    int getsum(pnode x){
        return x?x->sum:0;
    }
    void upd(int st,int en,pnode x,pnode &y,int pos,int val){
        y=new node(*x);
        if(st==en){
            y->sum+=val;
            return void();
        }
        int m=(st+en)/2;
        if(pos<=m)upd(st,m,x->l,y->l,pos,val);
        else upd(m+1,en,x->r,y->r,pos,val);
        y->sum=getsum(y->l)+getsum(y->r);
    }
    int fans(int st,int en,pnode x,pnode y,int s=0){
        if(st==en)return st;
        int m=(st+en)/2;
        if(getsum(y->r)-getsum(x->r)+s>=m+1)return fans(m+1,en,x->r,y->r,s);
        else return fans(st,m,x->l,y->l,s+getsum(y->r)-getsum(x->r));
    }
    void build(int st,int en,pnode &x){
        x=new node();
        if(st==en)return;
        int m=(st+en)/2;
        build(st,m,x->l);
        build(m+1,en,x->r);
    }
}tr;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n,q;cin>>n>>q;
    tr.build(1,2e5,tr.rt[0]);
    for(int i=1;i<=n;i++){
        int a;cin>>a;
        tr.upd(1,2e5,tr.rt[i-1],tr.rt[i],a,1);
    }
    for(int i=1;i<=q;i++){
        int l,r;cin>>l>>r;
        cout<<tr.fans(1,2e5,tr.rt[l-1],tr.rt[r])<<"\n";
    }
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50