Submission #1253955

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253955		goldenbull	Global Warming (CEOI18_glo)	C++17	100 / 100	36 ms	4288 KiB

glo

#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vi = vector<int>;

const char el = '\n';
const int maxn = 2e5+7;

struct Bitcoin {
    vi arr;
    int n;
    void init(int sz) {
        n = sz;
        arr.assign(n+1, 0);
    }
    void upd(int i, int v) {
        for (; i <= n; i+= i& -i) arr[i] = max(arr[i], v);
    }
    int get(int i) {
        int res = 0;
        for (; i > 0; i-= i& -i) res = max(res, arr[i]);
        return res;
    }
};

int n, cnt=1;
ll x;
ll a[maxn];
ll b[maxn];
ll c[maxn];
map<int, int> compress;

int pref[maxn], suf[maxn];
Bitcoin dp;

template<typename T>
void print(T a[], int n) { for (int i = 0; i < n; i++) cout << a[i] << ' '; cout << el; }

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
//    freopen("test.inp", "r", stdin);
//    freopen(".inp", "r", stdin);
//    freopen(".out", "w", stdout);

    cin >> n >> x;
    for (int i = 1; i <= n; i++) cin>>a[i];

    vll deck;
    for (int i = 1; i <= n; i++) {
        int pos = lower_bound(all(deck), a[i]) - deck.begin();
        if (pos == deck.size()) deck.pb(a[i]);
        else deck[pos] = a[i];
        pref[i] = pos+1;
    }

    deck.clear();
    for (int i = n; i >= 1; i--) {
        int pos = lower_bound(all(deck), x - a[i]) - deck.begin();
        suf[i] = pos+1;

        int id = lower_bound(all(deck), -a[i]) - deck.begin();
        if (id == deck.size()) deck.pb(-a[i]);
        else deck[id] = -a[i];
    }

    int res = 0;
    for (int i = 1; i <= n; i++) res = max(res, pref[i] + suf[i] - 1);

    cout << res;

    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