Submission #965422

#	Time	Username	Problem	Language	Result	Execution time	Memory
965422		efedmrlr	Abracadabra (CEOI22_abracadabra)	C++17	100 / 100	647 ms	57028 KiB

Main

// #pragma GCC optimize("O3,Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>

using namespace std;


#define lli long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()


void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}


const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e5+5;
const int ALPH = 26;
const int LGN = 25;
constexpr int MOD = 1e9+7;
int n,m,q;

struct SegT {
    vector<int> data;
    int sz;
    void reset(int s) {
        sz = s;
        data.assign(4*(sz + 3), 0);
    }
    void update(int tl, int tr, int v, int ind, int val) {
        if(tl == tr) {
            data[v] += val;
            return;
        }
        int tm = (tl + tr) >> 1;
        if(ind <= tm) {
            update(tl, tm, v << 1, ind, val);
        }
        else {
            update(tm + 1, tr, v << 1 ^ 1, ind, val);
        }
        data[v] = data[v << 1] + data[v << 1 ^ 1];
    }
    void update(int ind, int val) {
        update(0, sz, 1, ind, val);
    }
    int query(int tl, int tr, int v, int val) {
        if(tl == tr) {
            return tl;
        }   
        int tm = (tl + tr) >> 1;
        if(val <= data[v << 1]) {
            return query(tl, tm, v << 1, val);
        } 
        else {
            return query(tm + 1, tr, v << 1 ^ 1, val - data[v << 1]);
        }
    }
    int query(int val) {
        return query(0, sz, 1, val);
    }
    int query2(int tl, int tr, int v, int l, int r) {
        if(tl >= l && tr <= r) {
            return data[v];
        }
        if(tl > r || tr < l) {
            return 0;
        }
        int tm = (tl + tr) >> 1;
        return query2(tl, tm, v << 1, l, r) + query2(tm + 1, tr, v << 1 ^ 1, l, r);
    }
    int query2(int l, int r) {
        return query2(0, sz, 1, l, r);
    }
};  


vector<int> a, nxt;
vector<array<int,3> > comp;
set<array<int,3> > st;
vector<int> fin;
vector<array<int,3> > qu;
vector<int> res;
int tot = 0;
void calcn() {
    a[n + 1] = INF;
    vector<array<int,2> > tmp;
    for(int i = 1; i<=n + 1; i++) {
        while(tmp.size() && tmp.back()[0] < a[i]) {
            nxt[tmp.back()[1]] = i;
            tmp.pop_back();
        }
        tmp.pb({a[i], i});
    }

}   
int itr;
int t = 0;
SegT dt;
void get_fin(array<int,3> bl) {
    // cout << bl[0] << " " << bl[1] << " " << bl[2] << endl;
    for(int i = bl[2]; i >= bl[1]; i--) {
        fin[itr--] = a[i]; 
    }
}
void prt() {
    for(auto c : st) {
        cout << c[0] << " " << c[1] << " " << c[2] << "\n";
    }
}
void get_comp() {
    for(int l = 1; l <= n / 2;) {
        int r = min(n / 2, nxt[l] - 1);
        st.insert({a[l], l, r});
        comp.pb({a[l], l, r});
        tot += r - l + 1;
        l = nxt[l];
    }
    for(int l = n / 2 + 1; l <= n;) {
        int r = nxt[l] - 1;
        st.insert({a[l], l, r});
        comp.pb({a[l], l, r});
        tot += r - l + 1;
        l = nxt[l];
    }
    t++;
    while(1) {
        // prt();
        // cout << "round" << t << endl;
        // cout << "tot:" << tot << "\n";

        if(st.empty()) break;
        if(t == qu[q - 1][0]) break;
        auto last = st.end(); last--;
        while(tot - ((*last)[2] - (*last)[1] + 1) >= n / 2) {
            tot -= ((*last)[2] - (*last)[1] + 1);
            st.erase(last);            
            last = st.end(); last--;
        }
        auto el = *last;
        if(tot == n / 2) break;
        int len = el[2] - el[1] + 1;
        tot -= ((*last)[2] - (*last)[1] + 1);
        st.erase(last); 
        int ext = tot + len - n / 2;

        st.insert({el[0], el[1], el[2] - ext});
        comp.pb({el[0], el[1], el[2] - ext});
        tot += el[2] - ext - el[1] + 1;
        for(int l = el[2] - ext + 1; l <= el[2];) {
            int r = min(el[2], nxt[l] - 1);
            st.insert({a[l], l, r});
            tot += r - l + 1;
            comp.pb({a[l], l, r});
            l = nxt[l];
        } 
        t++;
    }
    // while(st.size()) { // TODO
    //     auto x = prev(st.end());
    //     get_fin(*x);
    //     st.erase(x);
    // }
    sort(all(comp));
    dt.reset((int)comp.size() + 5);
}
int ind = 0;
void go() {
    st.clear();
    tot = 0;
    for(; ind < q && qu[ind][0] == 0; ind++) {
        res[qu[ind][2]] = a[qu[ind][1]];
    }
    for(int l = 1; l <= n / 2;) {
        int r = min(n / 2, nxt[l] - 1);
        st.insert({a[l], l, r});
        tot += r - l + 1;
        dt.update((int)(lower_bound(all(comp), array<int,3>({a[l], l, r})) - comp.begin()), r - l + 1);
        l = nxt[l];
    }
    for(int l = n / 2 + 1; l <= n;) {
        int r = nxt[l] - 1;
        st.insert({a[l], l, r});
        tot += r - l + 1;
        dt.update((int)(lower_bound(all(comp), array<int,3>({a[l], l, r})) - comp.begin()), r - l + 1);
        l = nxt[l];
    }
    t++;
    while(1) {
        for(; ind < q && qu[ind][0] == t; ind++) {
            if(qu[ind][1] > itr) {
                res[qu[ind][2]] = fin[qu[ind][1]];
            }
            else {
                // cout << "que:" << qu[ind][0] << " " << qu[ind][1] << " " << qu[ind][2] << "\n";
                int cur = dt.query(qu[ind][1]);
                // cout << comp[cur][0] << " " << comp[cur][1] << " " << comp[cur][2] << "\n";
                int len = dt.query2(0, cur);
                // cout << "len:" << len << "\n";
                int fir = qu[ind][1] - len + comp[cur][2];
                // cout << "ind:" << qu[ind][1] - fir << "\n";

                res[qu[ind][2]] = a[fir]; 
            }
        }
        // prt();
        // cout << "round" << t << endl;
        // cout << "tot:" << tot << "\n";

        if(st.empty()) break;
        auto last = st.end(); last--;
        while(tot - ((*last)[2] - (*last)[1] + 1) >= n / 2) {
            tot -= ((*last)[2] - (*last)[1] + 1);
            dt.update(lower_bound(all(comp), *last) - comp.begin(), -((*last)[2] - (*last)[1] + 1));
            get_fin(*last);  // TODO
            
            st.erase(last);            
            assert(st.size() != 0);
            last = st.end(); last--;
        }
        auto el = *last;
        if(tot == n / 2) break;
        int len = el[2] - el[1] + 1;
        tot -= ((*last)[2] - (*last)[1] + 1);
        dt.update(lower_bound(all(comp), *last) - comp.begin(), -((*last)[2] - (*last)[1] + 1));
        st.erase(last); 
        int ext = tot + len - n / 2;

        st.insert({el[0], el[1], el[2] - ext});
        tot += el[2] - ext - el[1] + 1;
        dt.update(lower_bound(all(comp), array<int,3>({el[0], el[1], el[2] - ext})) - comp.begin(), el[2] - ext - el[1] + 1);
        for(int l = el[2] - ext + 1; l <= el[2];) {
            int r = min(el[2], nxt[l] - 1);
            st.insert({a[l], l, r});
            tot += r - l + 1;
            dt.update(lower_bound(all(comp), array<int,3>({a[l], l, r})) - comp.begin(), r - l + 1);
            l = nxt[l];
        } 
        t++;
    }
    while(st.size()) { // TODO
        auto x = prev(st.end());
        get_fin(*x);
        st.erase(x);
    }
    for(; ind < q; ind++) {
        res[qu[ind][2]] = fin[qu[ind][1]];
    }
}
inline void solve() {
    cin>>n>>q;
    a.resize(n + 2);
    nxt.resize(n + 1);
    fin.assign(n + 1, 0);
    qu.resize(q);
    itr = n;
    for(int i = 1; i<=n; i++) {
        cin >> a[i];
    }
    REP(i, q) {
        cin >> qu[i][0] >> qu[i][1];
        qu[i][2] = i;
    }
    sort(all(qu));
    calcn();
    get_comp();
    itr = n;
    res.assign(q, -1);
    t = 0;
    go();
    REP(i, q) cout << res[i] << "\n";
}
 
signed main() {

    fastio();
    int test = 1;
    //cin>>test;
    while(test--) {
        solve();
    }
    
}

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25