Submission #838772

#	Time	Username	Problem	Language	Result	Execution time	Memory
838772		arbuzick	Sequence (APIO23_sequence)	C++17	100 / 100	1373 ms	62412 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

const int R = 1 << 19;

int mn[R * 2], mx[R * 2], psh[R * 2];

void push(int node) {
    if (psh[node] != 0) {
        mn[node * 2] += psh[node];
        mx[node * 2] += psh[node];
        psh[node * 2] += psh[node];
        mn[node * 2 + 1] += psh[node];
        mx[node * 2 + 1] += psh[node];
        psh[node * 2 + 1] += psh[node];
    }
    psh[node] = 0;
}

void add(int ql, int qr, int val, int node = 1, int nl = 0, int nr = R) {
    if (ql <= nl && nr <= qr) {
        mn[node] += val;
        mx[node] += val;
        psh[node] += val;
        return;
    }
    if (qr <= nl || nr <= ql) {
        return;
    }
    push(node);
    int nm = (nl + nr) / 2;
    add(ql, qr, val, node * 2, nl, nm);
    add(ql, qr, val, node * 2 + 1, nm, nr);
    mn[node] = min(mn[node * 2], mn[node * 2 + 1]);
    mx[node] = max(mx[node * 2], mx[node * 2 + 1]);
}

pair<int, int> get(int ql, int qr, int node = 1, int nl = 0, int nr = R) {
    if (ql <= nl && nr <= qr) {
        return {mn[node], mx[node]};
    }
    if (qr <= nl || nr <= ql) {
        return {R, -R};
    }
    push(node);
    int nm = (nl + nr) / 2;
    auto p1 = get(ql, qr, node * 2, nl, nm), p2 = get(ql, qr, node * 2 + 1, nm, nr);
    mn[node] = min(mn[node * 2], mn[node * 2 + 1]);
    mx[node] = max(mx[node * 2], mx[node * 2 + 1]);
    return {min(p1.first, p2.first), max(p1.second, p2.second)};
}

int sequence(int n, vector<int> a) {
    vector<vector<int>> pos(n);
    for (int i = 0; i < n; ++i) {
        a[i]--;
        pos[a[i]].push_back(i);
    }
    for (int i = 0; i < n; ++i) {
        add(i + 1, n + 1, 1);
    }
    int ans = 1;
    vector<int> pr_min1(n), pr_min2(n), pr_max1(n), pr_max2(n), suf_min1(n), suf_min2(n), suf_max1(n), suf_max2(n);
    for (int vl = 0; vl < n; ++vl) {
        for (int i = 0; i < (int)pos[vl].size(); ++i) {
            auto p = get(0, pos[vl][i] + 1);
            pr_min1[i] = p.first;
            pr_max1[i] = p.second;
            p = get(pos[vl][i] + 1, n + 1);
            suf_min1[i] = p.first;
            suf_max1[i] = p.second;
        }
        for (auto p : pos[vl]) {
            add(p + 1, n + 1, -2);
        }
        for (int i = 0; i < (int)pos[vl].size(); ++i) {
            auto p = get(0, pos[vl][i] + 1);
            pr_min2[i] = p.first;
            pr_max2[i] = p.second;
            p = get(pos[vl][i] + 1, n + 1);
            suf_min2[i] = p.first;
            suf_max2[i] = p.second;
        }
        int l = 1, r = pos[vl].size() + 1;
        while (l < r - 1) {
            int m = (l + r) / 2;
            bool check = false;
            for (int i = 0; i + m <= (int)pos[vl].size(); ++i) {
                if (pr_min1[i] <= suf_max1[i + m - 1] && suf_min1[i + m - 1] <= pr_max1[i]) {
                    check = true;
                } else if (pr_min2[i] <= suf_max2[i + m - 1] && suf_min2[i + m - 1] <= pr_max2[i]) {
                    check = true;
                } else if (pr_max1[i] <= suf_min1[i + m - 1] && suf_max2[i + m - 1] <= pr_min2[i]) {
                    check = true;
                } else if (suf_max1[i] <= pr_min1[i + m - 1] && pr_max2[i + m - 1] <= suf_min2[i]) {
                    check = true;
                }
            }
            if (check) {
                l = m;
            } else {
                r = m;
            }
        }
        ans = max(ans, l);
    }
    return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 7 / 7
• Subtask 4: 12 / 12
• Subtask 5: 13 / 13
• Subtask 6: 22 / 22
• Subtask 7: 18 / 18