Submission #1169628

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169628		Thanhs	Curtains (NOI23_curtains)	C++20	0 / 100	23 ms	47432 KiB

curtains

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

#define name "TENBAI"
#define fi first
#define se second
#define endl '\n'
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))

mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}

const int NM = 5e5 + 5;
const int inf = 1e9;

int n, m, q, ans[NM];
set<int> s[NM];
vector<int> dt[NM];
pair<int, int> a[NM];
vector<pair<int, int>> Q[NM];
bool b[NM], f[NM];

void add(int i, int v)
{
    i = n - i + 1;
    for (; i <= n; i += i & -i)
        dt[i].push_back(v);
}

void del(int i)
{
    i = n - i + 1;
    for (; i <= n; i += i & -i)
        dt[i].pop_back();
}

int get(int i)
{
    i = n - i + 1;
    int res = inf;
    for (; i; i -= i & -i)
        if (dt[i].size())
            setmin(res, dt[i].back());
    return res;
}

void bu(int x)
{
}

void merge(int x, int y)
{
    if (s[x].size() < s[y].size())
        swap(s[x], s[y]);
    for (auto t : s[y])
        s[x].insert(t);
}

void solve()
{
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++)
        cin >> a[i].fi >> a[i].se;
    for (int i = 1; i <= q; i++)
    {
        int l, r;
        cin >> l >> r;
        Q[l].emplace_back(r, i);
    }
    sort(a + 1, a + 1 + m);
    for (int i = 1; i <= m; i++)
    {
        f[i] = !b[a[i].fi];
        b[a[i].fi] = 1;
    }
    for (int i = m; i >= 1; i--)
    {
        s[i].insert(a[i].se);
        while (1)
        {
            int t = get(a[i].fi);
            if (t == inf || a[t].fi > a[i].se + 1)
                break;
            merge(i, t);
            del(a[t].fi);
        }
        if (f[i])
            for (auto t : Q[a[i].fi])
                if (t.fi >= a[i].se)
                    ans[t.se] = s[i].count(t.fi);
        add(a[i].fi, i);
    }
    for (int i = 1; i <= q; i++)
        cout << (ans[i] ? "YES\n" : "NO\n");
}

signed main()
{
    if (fopen("in.txt", "r")) 
    {
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    }
    else if (fopen(name".inp", "r"))
    {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int tc = 1; 
    // cin >> tc;
    while (tc--)
        solve();
}

Compilation message (stderr)

curtains.cpp: In function 'int main()':
curtains.cpp:103:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |         freopen("in.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:104:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |         freopen("out.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:108:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:109:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 36
• Subtask 6: 0 / 20