Submission #1218781

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218781		countless	Progression (NOI20_progression)	C++20	0 / 100	210 ms	34772 KiB

Progression

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

#define sp <<" "<<
#define endl "\n"

const int BAD = 1e9;

struct segtree {
    struct data {
        int sum, pref, suff, best;

        data(int sum = -BAD, int pref = -BAD, int suff = -BAD, int best = -BAD) : sum(sum), pref(pref), suff(suff), best(best) {;;}
    };

    int l, r;
    data d;
    segtree *left, *right;

    // this can be made much simpler because we don't have non-negative entries
    inline data combine(const data &a, const data &b) {
        return data({
            a.sum + b.sum,
            max(a.pref, a.sum + b.pref),
            max(a.suff + b.sum, b.pref),
            max({a.best, b.best, a.suff + b.pref})
        });
    }

    inline void merge() {
        d = combine(left->d, right->d);
    }

    segtree(int l, int r, vector<int> &a) : l(l), r(r) {
        if (l == r) {
            if (a[l] == 0) d = data(1, 1, 1, 1);
            else d = data();
            left = right = nullptr;
            return;
        }

        int m = (l+r) / 2;
        left = new segtree(l, m, a);
        right = new segtree(m+1, r, a);
        merge();
    }

    data query(int ql, int qr) {
        if (ql > r or qr < l) return data();

        if (ql <= l and r <= qr) return d;

        return combine(left->query(ql, qr), right->query(ql, qr));
    }
};

void solve() {
    int n, q; cin >> n >> q;
    int sync = 0;
    n += sync;
    vector<int> a(n), d1, d2;
    for (int i = sync; i < n; i++) cin >> a[i];
    
    auto derive = [&](vector<int> &a) -> vector<int> {
        vector<int> res(n);
        for (int i = 1; i < n; i++) {
            res[i] = a[i] - a[i-1];
        }
        return res;
    };

    auto print = [&](vector<int> &a) -> void {
        for (auto &x : a) {
            cerr << x << " ";
        }   cerr << endl;
    };

    auto enact = [&]() -> void {
        d1 = derive(a);
        d2 = derive(d1);
    };

    auto debug = [&]() -> void {
        print(a), print(d1), print(d2);
        cerr << endl;
    };

    enact();
    // debug();

    segtree st(0, n-1, d2);

    int type, l, r, s, c;
    while (q--) {
        cin >> type;

        if (type == 1) {
            cin >> l >> r >> s >> c; l--, r--;
            l += sync, r += sync;

            assert(0);
        } else

        if (type == 2) {
            cin >> l >> r >> s >> c; l--, r--;
            l += sync, r += sync;

            assert(0);
        } else 

        if (type == 3) {
            cin >> l >> r; l--, r--;
            l += sync, r += sync;
            int sz = (r - l + 1);

            if (sz <= 2) {
                cout << sz << endl;
                continue;
            }

            int que = st.query(l+2, r).best;
            if (que < 0) que = 0;
            cout << que + 2 << endl;
        }
    }
}

signed main() {
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 15
• Subtask 3: 0 / 35
• Subtask 4: 0 / 11
• Subtask 5: 0 / 13
• Subtask 6: 0 / 17