Submission #1069028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1069028		_callmelucian	Global Warming (CEOI18_glo)	C++14	100 / 100	363 ms	22484 KiB

glo

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 4e5 + 5;
int a[mn], dp[mn];

vector<pii> cmp;

int getID (int targ, int p) {
    return lower_bound(all(cmp), make_pair(targ, p)) - cmp.begin();
}

struct IT {
    vector<int> tr;
    IT (int sz) : tr(4 * sz) {}

    void update (int pos, int val, int k, int l, int r) {
        if (pos < l || r < pos) return;
        if (l == r) {
            tr[k] = val;
            return;
        }
        int mid = (l + r) >> 1;
        update(pos, val, 2 * k, l, mid);
        update(pos, val, 2 * k + 1, mid + 1, r);
        tr[k] = max(tr[2 * k], tr[2 * k + 1]);
    }

    int query (int a, int b, int k, int l, int r) {
        if (b < l || r < a) return 0;
        if (a <= l && r <= b) return tr[k];
        int mid = (l + r) >> 1;
        return max(query(a, b, 2 * k, l, mid), query(a, b, 2 * k + 1, mid + 1, r));
    }
} preTree(mn), sfxTree(mn);

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, x; cin >> n >> x;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        cmp.emplace_back(a[i], i);
        cmp.emplace_back(a[i] - x, i);
    }
    sort(all(cmp)); filter(cmp);

    int mx = cmp.size() - 1, ans = 0;
    for (int i = n; i >= 1; i--) {
        dp[i] = sfxTree.query(getID(a[i], INT_MAX), mx, 1, 0, mx) + 1;
        sfxTree.update(getID(a[i], i), dp[i], 1, 0, mx);
    }

    for (int i = 1; i <= n; i++) {
        sfxTree.update(getID(a[i], i), 0, 1, 0, mx);
        dp[i] = preTree.query(0, getID(a[i] - x, 0) - 1, 1, 0, mx) + 1;
        preTree.update(getID(a[i] - x, i), dp[i], 1, 0, mx);
        ans = max(ans, dp[i] + sfxTree.query(getID(a[i] - x, INT_MAX), mx, 1, 0, mx));
    }
    cout << ans;

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25