Submission #1273973

#	Time	Username	Problem	Language	Result	Execution time	Memory
1273973		antonn	Growing Vegetables is Fun 5 (JOI24_vegetables5)	C++20	67 / 100	724 ms	28628 KiB

Main

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 3e5 + 7;

int n;
int a[2 * N], b[N], c[N];
int l[2 * N], r[2 * N], lc[2 * N], rc[2 * N];
pair<int, int> pref[2 * N], suff[2 * N], mid_pref[2 * N], mid_suff[2 * N];

pair<int, int> inter(pair<int, int> a, pair<int, int> b) {
    return {max(a.first, b.first), min(a.second, b.second)};
}

bool check(int mid) {
    {
        int ptrl = 1, ptrr = 0;
        for (int i = 1; i <= n; ++i) {
            while (ptrr + 1 <= n && b[ptrr + 1] <= a[i] + mid) ++ptrr;
            while (ptrl <= n && b[ptrl] < a[i] - mid) ++ptrl;
            l[i] = ptrl;
            r[i] = ptrr;
        }
        for (int i = 2 * n; i >= n + 1; --i) {
            while (ptrr + 1 <= n && b[ptrr + 1] <= a[i] + mid) ++ptrr;
            while (ptrl <= n && b[ptrl] < a[i] - mid) ++ptrl;
            l[i] = ptrl;
            r[i] = ptrr;
        }
    }
    {
        int ptrl = 1, ptrr = 0;
        for (int i = 1; i <= n; ++i) {
            while (ptrr + 1 <= n && c[ptrr + 1] <= a[i] + mid) ++ptrr;
            while (ptrl <= n && c[ptrl] < a[i] - mid) ++ptrl;
            lc[i] = ptrl;
            rc[i] = ptrr;
        }
        for (int i = 2 * n; i >= n + 1; --i) {
            while (ptrr + 1 <= n && c[ptrr + 1] <= a[i] + mid) ++ptrr;
            while (ptrl <= n && c[ptrl] < a[i] - mid) ++ptrl;
            lc[i] = ptrl;
            rc[i] = ptrr;
        }
    }
    bool ret = 0;
    for (int it = 0; it < 2; ++it) {
        pref[0] = {-1e9, 1e9};
        int cnt = 0;
        for (int i = 1; i <= 2 * n; ++i) {
            ++cnt;
            pref[i] = inter(pref[i - 1], {lc[i] - cnt, rc[i] - cnt});
        }
        suff[2 * n + 1] = {-1e9, 1e9};
        cnt = 0;
        for (int i = 2 * n; i >= 1; --i) {
            ++cnt;
            suff[i] = inter(suff[i + 1], {lc[i] - cnt, rc[i] - cnt});
        }
        mid_pref[n] = {-1e9, 1e9};
        cnt = 0;
        for (int i = n + 1; i <= 2 * n; ++i) {
            ++cnt;
            mid_pref[i] = inter({mid_pref[i - 1].first - 1, mid_pref[i - 1].second - 1}, {l[i], r[i]});
        }
        mid_suff[n + 1] = {-1e9, 1e9};
        cnt = 0;
        for (int i = n; i >= 1; --i) {
            ++cnt;
            mid_suff[i] = inter({mid_suff[i + 1].first - 1, mid_suff[i + 1].second - 1}, {l[i], r[i]});
        }
        for (int i = 1; i <= n; ++i) {
            pair<int, int> f1 = inter(pref[i - 1], {suff[i + n].first - (i - 1), suff[i + n].second - (i - 1)});
            pair<int, int> f2 = inter(mid_suff[i], {mid_pref[i + n - 1].first - (n - i + 1), mid_pref[i + n - 1].second - (n - i + 1)});
            if (f1.first <= f1.second && f2.first <= f2.second) {
                ret = 1;
            }
        }
        for (int i = 1; i <= n; ++i) swap(b[i], c[i]);
        for (int i = 1; i <= 2 * n; ++i) swap(l[i], lc[i]);
        for (int i = 1; i <= 2 * n; ++i) swap(r[i], rc[i]);
    }
    return ret;
}

int solve(vector<int> v, int a[]) {
    sort(v.begin(), v.end());
    int ans = 0;
    for (int i = 1; i <= n; ++i) {
        ans = max(ans, abs(v[i - 1] - a[i]));
    }
    return ans;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for (int i = 1; i <= 2 * n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) cin >> b[i];
    for (int i = 1; i <= n; ++i) cin >> c[i];
    sort(b + 1, b + n + 1);
    sort(c + 1, c + n + 1);
    
    if (n <= 2000) {
        int ans = 1e9;
        for (int i = 1; i + n - 1 <= 2 * n; ++i) {
            vector<int> v1, v2;
            for (int j = 1; j <= 2 * n; ++j) {
                if (i <= j && j <= i + n - 1) {
                    v1.push_back(a[j]);
                } else {
                    v2.push_back(a[j]);
                }
            }
            ans = min(ans, max(solve(v1, b), solve(v2, c)));
            ans = min(ans, max(solve(v1, c), solve(v2, b)));
        }
        cout << ans << "\n";
        return 0;
    }
    
    int low = 0, high = 1e9, sol = 0;
    while (low <= high) {
        int mid = (low + high) / 2;
        if (check(mid)) {
            sol = mid;
            high = mid - 1;
        } else {
            low = mid + 1;
        }
    }
    cout << sol << "\n";
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 21 / 21
• Subtask 4: 37 / 37
• Subtask 5: 0 / 33