Submission #503075

#	Time	Username	Problem	Language	Result	Execution time	Memory
503075		blue	Triple Jump (JOI19_jumps)	C++17	100 / 100	899 ms	105868 KiB

jumps

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

using ll = long long;
using vll = vector<ll>;
using vi = vector<int>;

const int maxN = 500'000;
const ll INF = 1'000'000'000'000'000'000LL;


int N, Q;
vll A;
const int Z = (1<<19);

struct segtree
{
    vll lp = vll(Z<<1, -INF);
    vll half = vll(Z<<1, 0);
    vll full = vll(Z<<1, -INF);

    void build(int i, int l, int r)
    {
        if(l == r)
        {
            half[i] = A[l];
        }
        else
        {
            build(2*i, l, (l+r)/2);
            build(2*i+1, (l+r)/2+1, r);
            half[i] = max(half[2*i], half[2*i+1]);
        }
    }

    void deploy(int i, int l, int r, int L, int R, ll V)
    {
        if(R < l || r < L) return;
        else if(L <= l && r <= R)
        {
            // cerr << "direct deployed A: " << i << ' ' << l << ' ' << r << ' ' << lp[i] << ' ' << full[i] << '\n';
            lp[i] = max(lp[i], V);
            full[i] = max(full[i], half[i] + lp[i]);
            // cerr << "direct deployed B: " << i << ' ' << l << ' ' << r << ' ' << lp[i] << ' ' << full[i] << '\n';
        }
        else
        {
            deploy(2*i, l, (l+r)/2, L, R, V);
            deploy(2*i+1, (l+r)/2+1, r, L, R, V);

            full[i] = max({half[i] + lp[i], full[2*i], full[2*i+1]});

            // cerr << "full " << i << ' ' << l << ' ' << r << " = " << full[i] << '\n';
        }
    }

    pair<ll, ll> rangemax(int i, int l, int r, int L, int R)
    {
        if(R < l || r < L) return {-INF, -INF};
        else if(L <= l && r <= R)
        {
            // cerr << "range: " << i << ' ' << l << ' ' << r << " - " << full[i] << ' ' << half[i] << '\n';
            return {full[i], half[i]};
        }
        else
        {
            pair<ll, ll> lft =rangemax(2*i, l, (l+r)/2, L, R);
            pair<ll, ll> rgt = rangemax(2*i+1, (l+r)/2+1, r, L, R);
            return {max({lft.first, rgt.first, lft.second + lp[i], rgt.second + lp[i]}), max(lft.second, rgt.second)};
        }
    }
};

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> N;

    A = vll(1+N+1);
    for(int i = 1; i <= N; i++) cin >> A[i];

    vi re[1+N];

    A[N+1] = INF;

    vi st{N+1};
    for(int i = N; i >= 1; i--)
    {
        while(A[i] > A[st.back()])
        {
            // cerr << "pair: " << i << ' ' << st.back() << '\n';
            re[i].push_back(st.back());
            st.pop_back();
        }
        if(st.back() != N+1)
            re[i].push_back(st.back());

        // if(st.back() != N+1) cerr << "npair: " << i << " " << st.back() << '\n';

        st.push_back(i);
    }


    cin >> Q;
    vi l(1+Q), r(1+Q), lqi[1+N];
    for(int j = 1; j <= Q; j++)
    {
        cin >> l[j] >> r[j];
        lqi[l[j]].push_back(j);
    }

    vll res(1+Q, -INF);

    segtree S;
    S.build(1, 1, N);

    // for(int f = 1; f <= N; f++) cerr << S.rangemax(1, 1, N, f, f).first << ' ';
    // cerr << '\n';

    for(int li = N; li >= 1; li--)
    {
        // cerr << "\n\n\n\n";
        // if(li == 2) cerr << "!!!! " << li << ' ' << S.full[3] << '\n';
        for(int ri: re[li])
        {
            if(ri + (ri - li) > N) continue;
            S.deploy(1, 1, N, ri + (ri - li), N, A[li] + A[ri]);
            // cerr << "deploying " << li << ' ' << ri << " : " << A[li]+A[ri] << " to range " << ri + (ri - li) << ' ' << N << '\n';

            // cerr << "segtree = ";
            // for(int f = 1; f <= N; f++) cerr << S.rangemax(1, 1, N, f, f).first << ' ';
            // cerr << '\n';
        }
        // cerr << "\n\n";
        // if(li == 2) cerr << "!!!! " << li << ' ' << S.full[3] << '\n';

        // if(li == 2)
        // {
        //     cerr << "segtree = \n";
        //     for(int f = 1; f <= N; f++)
        //     {
        //         cerr << "f = " << f << " : " << S.rangemax(1, 1, N, f, f).first << '\n';
        //     }
        // }

        // if(li == 2) cerr << "!!!! " << li << ' ' << S.full[3] << '\n';

        for(int q: lqi[li])
        {
            // cerr << "answering: " << q << '\n';
            res[q] = S.rangemax(1, 1, N, li, r[q]).first;
        }
    }

    for(int j = 1; j <= Q; j++) cout << res[j] << '\n';
}

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 27 / 27
• Subtask 4: 54 / 54