Submission #1259752

#	Time	Username	Problem	Language	Result	Execution time	Memory
1259752		phtung	Curtains (NOI23_curtains)	C++20	9 / 100	1596 ms	2492 KiB

curtains

#include <bits/stdc++.h>

using namespace std;

#define name "IO"
#define int long long 

const int inf = 1e18 + 7; 
const int maxn = 5e5 + 5;
int n, m, q;

struct segTree
{
    vector<int> st, lazy;

    segTree(int n)
    {
        st.resize(4 * n + 5, 0);
        lazy.resize(4 * n + 5, 0); 
    }

    void clear()
    {
        fill(st.begin(), st.end(), 0);
        fill(lazy.begin(), lazy.end(), 0); 
    }

    void down(int id, int l, int r)
    {
        if(!lazy[id]) return;
        st[id] += lazy[id];

        if(l != r)
        {
            lazy[id * 2] += lazy[id];
            lazy[id * 2 + 1] += lazy[id]; 
        }
        lazy[id] = 0; 
    }

    void update(int id, int l, int r, int u, int v, int val)
    {
        down(id, l, r);
        if(l > v || r < u) return;
        if(l >= u && r <= v)
        {
            lazy[id] += val;
            down(id, l, r);
            return; 
        }
        int m = l + r >> 1;
        update(id * 2, l, m, u, v, val);
        update(id * 2 + 1, m + 1, r, u, v, val);
        st[id] = min(st[id * 2], st[id * 2 + 1]); 
    }

    int get(int id, int l, int r, int u, int v)
    {
        down(id, l, r); 
        if(l > v || r < u) return inf; 
        if(l >= u && r <= v) return st[id];
        int m = l + r >> 1;
        return min(get(id * 2, l, m, u, v), get(id * 2 + 1, m + 1, r, u, v)); 
    }
};

bool check(int u, int v, int l, int r)
{
    if(u < l || u > r) return 0; 
    if(v < l || v > r) return 0;
    return 1; 
}

void solve()
{
    cin >> n >> m >> q; 

    vector<pair<int,int>> curtain; 
    for(int i = 1; i <= m; i++)
    {
        int l, r;
        cin >> l >> r; 
        curtain.push_back({l, r}); 
    }

    segTree st(n); 

    for(int i = 1; i <= q; i++)
    {
        st.clear(); 
        int l, r;
        cin >> l >> r;
        
        for(auto [left, right] : curtain)
        {
            if(check(left, right, l, r)) st.update(1, 1, n, left, right, 1); 
        }

        if(st.get(1, 1, n, l, r) > 0) cout << "YES\n";

        else cout << "NO\n";
    }
}

signed main()
{
    if (fopen (name".INP", "r"))
    {
        freopen (name".INP", "r", stdin);
        freopen (name".OUT", "w", stdout);
    }

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    
    clock_t start = clock(); 

    int t = 1;

    while(t--) solve(); 

    std::cerr << "Time: " << clock() - start << "ms\n";

    return 0; 

}

Compilation message (stderr)

curtains.cpp: In function 'int main()':
curtains.cpp:109:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |         freopen (name".INP", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:110:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         freopen (name".OUT", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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