Submission #868927

#	Time	Username	Problem	Language	Result	Execution time	Memory
868927		rockstar	Triple Jump (JOI19_jumps)	C++17	100 / 100	958 ms	136528 KiB

jumps

//#pragma GCC optimize("O3,unroll-loops,inline,fast-math")

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

#define all(a) (a).begin(), (a).end()
#define int ll

constexpr int INF = numeric_limits<int>::max() / 2;

struct node {
    int c = 0, res = 0;

    node(int a) {
        c = a;
        res = -INF;
    }

    node() {}
};

node operator+(node a, node b) {
    node x;
    x.res = max(a.res, b.res);
    x.c = max(a.c, b.c);
    return x;
}

struct segment_tree {
    vector<node> tree;
    vector<int> maxupd;
    int n;

    segment_tree(vector<int> &a) {
        n = a.size();
        tree.resize(4 * n);
        maxupd.resize(4 * n, -INF);
        build(1, 0, n - 1, a);
    }

    void build(int v, int tl, int tr, vector<int> &a) {
        if (tl == tr) {
            tree[v] = node(a[tl]);
            return;
        }
        int tm = (tl + tr) / 2;
        build(2 * v, tl, tm, a);
        build(2 * v + 1, tm + 1, tr, a);
        tree[v] = tree[v * 2] + tree[v * 2 + 1];
    }

    void push(int v, int tl, int tr) {
        if (tl != tr)
            maxupd[v * 2] = max(maxupd[v * 2], maxupd[v]), maxupd[v * 2 + 1] = max(maxupd[v * 2 + 1], maxupd[v]);
        tree[v].res = max(tree[v].res, tree[v].c + maxupd[v]);
    }

    void upd(int v, int tl, int tr, int l, int r, int val) {
        push(v, tl, tr);
        if (r < tl || tr < l)
            return;
        if (l <= tl && tr <= r) {
            maxupd[v] = max(maxupd[v], val);
            push(v, tl, tr);
            return;
        }
        int tm = (tl + tr) / 2;
        upd(v * 2, tl, tm, l, r, val);
        upd(v * 2 + 1, tm + 1, tr, l, r, val);
        tree[v] = tree[v * 2] + tree[v * 2 + 1];
    }

    int get(int v, int tl, int tr, int l, int r) {
        push(v, tl, tr);
        if (r < tl || tr < l)
            return 0;
        if (l <= tl && tr <= r)
            return tree[v].res;
        int tm = (tl + tr) / 2;
        return max(get(2 * v, tl, tm, l, r), get(2 * v + 1, tm + 1, tr, l, r));
    }

    void upd(int l, int val) {
        upd(1, 0, n - 1, l, n - 1, val);
    }

    int get(int l, int r) {
        return get(1, 0, n - 1, l, r);
    }
};

void solve() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int &i: a)
        cin >> i;
    vector<pair<int, int>> st;
    vector<vector<pair<int, int>>> ab(n);
    for (int i = 0; i < n; ++i) {
        while (!st.empty() && st.back().first <= a[i]) {
            if (2 * i - st.back().second < n)
                ab[st.back().second].push_back({i, st.back().first + a[i]});
            st.pop_back();
        }
        if (!st.empty()) {
            if (2 * i - st.back().second < n)
                ab[st.back().second].push_back({i, st.back().first + a[i]});
        }
        st.push_back({a[i], i});
    }
    int q;
    cin >> q;
    vector<vector<pair<int, int>>> query(n);
    for (int i = 0; i < q; ++i) {
        int l, r;
        cin >> l >> r;
        --l, --r;
        query[l].push_back({r, i});
    }
    segment_tree tr(a);
    vector<int> res(q);
    for (int i = n - 1; i >= 0; --i) {
        for (auto [b, sum]: ab[i])
            tr.upd(2 * b - i, sum);
        for (auto [r, ind] : query[i])
            res[ind] = tr.get(i, r);
    }
    for (int i : res)
        cout << i << '\n';
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1;
//    cin >> t;
    while (t--)
        solve();
}

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