verify/yosupo/data-structure/persistent_queue.test.cpp

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Last update: 2024-10-31 23:18:18+07:00
Problem: https://judge.yosupo.jp/problem/persistent_queue

Depends on

Code

#define PROBLEM "https://judge.yosupo.jp/problem/persistent_queue"
#include "template.hpp"
#include "data-structure/persistent-queue.hpp"

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    PersistentQueue<int> q;
    for(int i=0;i<n;i++){
        int op,t;
        cin >> op >> t;
        if(op==0){
            int x;
            cin >> x;
            q.push(t,x);
        }else{
            cout << q.front(t) << "\n";
            q.pop(t);
        }
    }
}

#line 1 "verify/yosupo/data-structure/persistent_queue.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/persistent_queue"
#line 1 "template.hpp"
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

using ll = long long;
using db = long double;
using vi = vector<int>;
using vl = vector<ll>;
using vd = vector<db>;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pdd = pair<db,db>;
const int INF=INT_MAX/2;
const int MOD=998244353;
const int MOD2=1000000007;
const ll LINF=LLONG_MAX/2;
const db DINF=numeric_limits<db>::infinity();
const db EPS=1e-9;
const db PI=acos(db(-1));

template<class T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<class T>
using ordered_multiset = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
#line 2 "data-structure/persistent-queue.hpp"

/**
 * Author: Teetat T.
 * Date: 2024-06-28
 * Description: Persistent Queue.
 */

template<class T>
struct PersistentQueue{
    int n,lg;
    vector<T> dat;
    vector<int> back_id,len;
    vector<vector<int>> par;
    PersistentQueue():n(1),lg(1),dat(0),back_id(0),len(0),par(1,{0}){}
    void calc_par(){
        if(n<(1<<lg))return;
        for(int i=0;i<n;i++)par[i].emplace_back(par[par[i][lg-1]][lg-1]);
        lg++;
    }
    int push(int t,const T &val){
        dat.emplace_back(val);
        back_id.emplace_back(n);
        len.emplace_back((t==-1?0:len[t])+1);
        par.emplace_back(vector<int>(lg,0));
        par[n][0]=t==-1?0:back_id[t];
        for(int i=1;i<lg;i++)par[n][i]=par[par[n][i-1]][i-1];
        n++;
        calc_par();
        return back_id.size()-1;
    }
    int pop(int t){
        back_id.emplace_back(back_id[t]);
        len.emplace_back(len[t]-1);
        return back_id.size()-1;
    }
    T front(int t){
        int d=size(t)-1;
        int x=back_id[t];
        for(int j=lg-1;j>=0;j--)if(d>>j&1)x=par[x][j];
        return dat[x-1];
    }
    int size(int t){
        return len[t];
    }
};

#line 4 "verify/yosupo/data-structure/persistent_queue.test.cpp"

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    PersistentQueue<int> q;
    for(int i=0;i<n;i++){
        int op,t;
        cin >> op >> t;
        if(op==0){
            int x;
            cin >> x;
            q.push(t,x);
        }else{
            cout << q.front(t) << "\n";
            q.pop(t);
        }
    }
}