Submission #1330014

#	Time	Username	Problem	Language	Result	Execution time	Memory
1330014		vuviet	Global Warming (CEOI18_glo)	C++20	100 / 100	211 ms	8408 KiB

glo

/**
 *     Author:       trviet
 *     Studies at:   Le Hong Phong High School for the Gifted
**/

#include <bits/stdc++.h>

#define ____vuviet__ signed main
#define taskname "trviet"

using namespace std;

#define all(x) x.begin(), x.end()
constexpr int maxn = 2e5 + 5;
int n, x, t[maxn], f[maxn], g[maxn];
vector<int> values;

struct SegmentTree
{
    int sz;
    vector<int> st;
    SegmentTree(int sz)
    {
        this->sz = sz;
        st.resize(2 * sz + 5, 0);
    }

    void update(int i, int v)
    {
        st[i += sz] = v;
        i /= 2;
        while (i > 0) {
            st[i] = max(st[i * 2], st[i * 2 + 1]), i /= 2;
        }
    }
 
    int query(int l, int r)
    {
        int res = 0;
        l += sz, r += sz + 1;
        while (l < r)
        {
            if (l & 1) res = max(res, st[l++]);
            if (r & 1) res = max(res, st[--r]);
            l /= 2, r /= 2;
        }
        return res;
    }
};

int idx(int v)
{
    return lower_bound(all(values), v) - values.begin() + 1;
}

void solvebytrviet()
{
    cin >> n >> x;
    for (int i = 1; i <= n; ++i)
    {
        cin >> t[i], f[i] = g[i] = 1;
        values.push_back(t[i]);
    }
    sort(all(values));
    values.resize(unique(all(values)) - values.begin());
    int m = values.size();
    SegmentTree l(m), r(m), segtree(m);
    for (int i = 1; i <= n; ++i)
    {
        f[i] = 1 + l.query(1, idx(t[i]) - 1);
        l.update(idx(t[i]), f[i]);
    }
    for (int i = n; i >= 1; --i)
    {
        g[i] = 1 + r.query(idx(t[i]) + 1, m);
        r.update(idx(t[i]), g[i]);
    }
    int ans = 0;
    for (int i = n; i >= 1; --i)
    {
        int p = idx(t[i] - x + 1);
        int best = (p <= m ? segtree.query(p, m) : 0);
        ans = max(ans, f[i] + best);
        segtree.update(idx(t[i]), g[i]);
    }
    cout << ans;
}

void freopen_stdio(string speech)
{
    cin.tie(0)->sync_with_stdio(0);
    cerr << speech << "\n";
    if (fopen(taskname ".inp", "r"))
    {
        freopen(taskname ".inp", "r", stdin);
        freopen(taskname ".out", "w", stdout);
    }
}

____vuviet__()
{
    freopen_stdio("!@#$%^&*()=_+");
    int t = 1;
    // cin >> t;
    while (t-- > 0)
        solvebytrviet();
    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'void freopen_stdio(std::string)':
glo.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         freopen(taskname ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen(taskname ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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