Submission #471138

#	Time	Username	Problem	Language	Result	Execution time	Memory
471138		zxcvbnm	Global Warming (CEOI18_glo)	C++14	62 / 100	105 ms	11404 KiB

glo

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int ll
void get(vector<int>& suff, vector<int>& suff_len, vector<int> a) {
    reverse(a.begin(), a.end());
    set<int> s;

    for(int i = 0; i < (int) a.size(); i++) {
        auto it = s.upper_bound(a[i]);
        if (it == s.begin()) {
            s.insert(a[i]);
        }
        else {
            it--;
            if (*it < a[i]) {
                s.erase(it);
                s.insert(a[i]);
            }
        }
        suff.push_back(*s.begin());
        suff_len.push_back(s.size());
//        for(int j : suff) {
//            cout << j << " ";
//        } cout << "\n";
    }
    reverse(suff.begin(), suff.end());
    reverse(suff_len.begin(), suff_len.end());
}
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, x;
    cin >> n >> x;
    vector<int> a(n);
    for(int& i : a) {
        cin >> i;
    }

    int ans = 0;
    vector<int> suff, suff_len;
    get(suff, suff_len, a);
    for(int& i : suff) {
        i += x;
    }

    ans = *max_element(suff_len.begin(), suff_len.end());
//    suff.push_back(0);
//    suff_len.push_back(0);

    vector<int> dp;
    for(int i = 0; i < n; i++) {
        int pos = lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin();
        if (pos == (int) dp.size()) {
            dp.push_back(a[i]);
        }
        else {
            dp[pos] = a[i];
        }

        ans = max(ans, (int) dp.size());
        ans = max(ans, suff_len[i]);
        if (i == n-1) continue;

        auto it = lower_bound(dp.begin(), dp.end(), suff[i+1]);
        ans = max(ans, (it - dp.begin()) + suff_len[i+1]);
    }

    cout << ans << "\n";
//    for(int i = 0; i < n; i++) {
//        cout << suff[i] << " " << suff_len[i] << "\n";
//    }
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25