Submission #1101918

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101918		anhthi	Global Warming (CEOI18_glo)	C++14	100 / 100	216 ms	27316 KiB

glo

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define heap priority_queue
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)

template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }

template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }

template <class X>
    inline void compress(X &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }

int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }

const ll oo = (ll) 1e17;
const int INF = (int) 1e9 + 7, MOD = (int) 1e9 + 7;

const int N = 2e5 + 15;

void add(int &x, int y) { x += y; if (x >= MOD) x -= MOD; }
void sub(int &x, int y) { x -= y; if (x < 0) x += MOD; }

int n;
ll x, a[N], ID[N][3];

struct Seg {
    int n;
    vector<ll> st;
    Seg(int n) : n(n) {
        st.resize(2 * n + 5);
    }
    void upd(int p, ll d) {
        p += n;
        maximize(st[p], d);
        while (p > 1) {
            p >>= 1;
            st[p] = max(st[2 * p], st[2 * p + 1]);
        }
    }
    ll query(int l, int r) {
        l += n;
        r += n + 1;
        ll ans = 0;
        for (; l < r; l >>= 1, r >>= 1) {
            if (l & 1) maximize(ans, st[l++]);
            if (r & 1) maximize(ans, st[--r]);
        }
        return ans;
    }
    void reset() { st.assign(2 * n + 5, 0); }
};

int main(void) {
    // think what before starting to code
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> x;
    forn(i, 1, n) cin >> a[i];

    vector<ll> cps;
    forn(i, 1, n) forn(j, -1, 1) {
        cps.pb(a[i] + j * x);
    }
    compress(cps);
    forn(i, 1, n) forn(j, 0, 2) {
        ID[i][j] = lower_bound(all(cps), a[i] + (j - 1) * x) - cps.begin() + 1;    
    }
    int m = sz(cps);
    
    Seg s(m);
    vector<ll> pf(n + 1, 0), sf(n + 1, 0);
    forn(i, 1, n) {
        pf[i] = s.query(1, ID[i][1] - 1) + 1;
        s.upd(ID[i][1], pf[i]);
    }
    s.reset();
    ford(i, n, 1) {
        sf[i] = s.query(ID[i][1] + 1, m) + 1;
        s.upd(ID[i][1], sf[i]);
    }
    s.reset();
    ll ans = 0;
    
    forn(i, 1, n) {
        maximize(ans, sf[i] + s.query(1, ID[i][2] - 1));
        s.upd(ID[i][1], pf[i]);
    }

    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