Submission #970348

#	Time	Username	Problem	Language	Result	Execution time	Memory
970348		efedmrlr	Triple Jump (JOI19_jumps)	C++17	100 / 100	436 ms	94684 KiB

jumps

#include <bits/stdc++.h>

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

using namespace std;

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

const int N = 1e5 + 5;
const int INF = 1e9 + 500;

struct Node {
    int ar, f, mx;
    Node() : ar(0), f(0), mx(0) {}
    Node comb(Node &oth) {
        Node ret;
        ret.ar = max(ar, oth.ar);
        ret.f = max(f, oth.f);
        ret.mx = max(mx, oth.mx);
        ret.mx = max(ret.mx, f + oth.ar);
        return ret;
    }
};

struct SegT {
    vector<Node> st;
    int n;
    void reset(int nn) {
        n = nn;
        st.assign(2*(n + 3), Node());
    }
    void build() {
        for(int i = n - 1; i>0; i--) {
            st[i] = st[i << 1].comb(st[(i << 1) | 1]); 
        } 
    }
    void update(int ind, int val) {
        ind += n;
        st[ind].f = max(st[ind].f, val);
        st[ind].mx = max(st[ind].mx, st[ind].f + st[ind].ar);
        for(; ind > 1; ind >>= 1) {
            if(ind & 1) ind ^= 1;
            st[ind >> 1] = st[ind].comb(st[ind | 1]);
        }
    }
    int query(int l, int r) {
        Node lret, rret;
        for(l += n, r += n; l < r; l >>= 1, r >>= 1) {
            if(l & 1) lret = lret.comb(st[l++]);
            if(r & 1) rret = st[--r].comb(rret);
        }

        return lret.comb(rret).mx;
    }
    int queryc(int l, int r) {
        return query(l, r + 1);
    }
};

int n, q;
vector<int> a;
vector<array<int, 3> > qu;
vector<vector<int> > pr;

void solve() {
    cin >> n;
    a.resize(n + 1);
    for(int i = 1; i<=n; i++) {
        cin >> a[i];
    }
    cin >> q;
    qu.resize(q);
    REP(i, q) {
        cin >> qu[i][0] >> qu[i][1];
        qu[i][2] = i;
    }
    vector<array<int, 2> > stck;
    pr.assign(n + 1, vector<int>());
    for(int i = 1; i<=n; i++) {
        while(stck.size() && stck.back()[0] <= a[i]) {
            pr[stck.back()[1]].pb(i);
            stck.pop_back();
        }
        if(stck.size()) {
            pr[stck.back()[1]].pb(i);
        }
        stck.pb({a[i], i});
    }
    SegT st;
    st.reset(n + 1);
    for(int i = 1; i <= n; i++) {
        st.st[i + st.n].ar = a[i];
    }
    st.build();
    sort(rall(qu));
    vector<int> res(q + 1);
    // for(int i = 1; i <= n; i++) {
    //     for(int j : pr[i]) {
    //         cout << i << " " << j << "\n";
    //     }
    // }
    int cur = n;
    for(auto &c : qu) {
        while(cur > c[0]) {
            cur--;
            for(auto x : pr[cur]) {
                if(2 * x - cur > n) continue;
                st.update(2 * x - cur, a[x] + a[cur]);
            }
        }
        res[c[2]] = st.queryc(c[0], c[1]);
    }

    for(int i = 0; i < q; i++) {
        cout << res[i] << "\n";
    }
}

signed main() {
    fastio();
    solve();
}

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