Submission #1169587

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169587		nathan4690	Curtains (NOI23_curtains)	C++20	100 / 100	757 ms	94508 KiB

curtains

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define f1(i,n) for(int i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn=1e6+5, inf=1e18;

struct Value{
    int le = 1e9, ri = -1e9;
    Value(int le=1e9, int ri=-1e9): le(le), ri(ri){};
    Value operator+(const Value &rhs) const{
        // Merge two nodes
        Value res;
        if(le == 1e9) res = rhs;
        else if(rhs.le == 1e9) res = *this;
        else if(ri >= rhs.le - 1){
            res.le = min(le, rhs.le);
            res.ri = max(ri, rhs.ri);
        }else res = rhs;
        return res;
    }
};

template<class T>
struct SegmentTree{
    int n;
    vector<T> st;
    SegmentTree(){};
    SegmentTree(int n): n(n), st(4*n+1){};
    void _upd1(int idx, int l, int r, int i, const T &v){
        if(i < l || r < i) return;
        if(l == r){
            st[idx] = st[idx] + v;
            return;
        }
        int mid = (l + r) / 2;
        _upd1(idx*2, l, mid, i, v);
        _upd1(idx*2+1, mid+1, r, i, v);
        st[idx] = st[idx*2] + st[idx*2+1];
    }
    inline void updatePoint(int position, const T &value){
        _upd1(1,1,n,position,value);
    }
    T _get(int idx, int l, int r, int u, int v){
        if(v < l || r < u) return T();
        if(u <= l && r <= v) return st[idx];
        int mid = (l + r) / 2;
        return _get(idx*2, l, mid, u, v) + _get(idx*2+1, mid+1, r, u, v);
    }
    inline T getRange(int left_, int right_){
        return _get(1,1,n,left_, right_);
    }
};

#define SegTree SegmentTree<Value>

int n, m, q;
pair<int,int> a[maxn];
vector<pair<int,int>> qu[maxn];
vector<int> upd[maxn];
SegTree st;
bool ans[maxn];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if(fopen(__file_name ".inp", "r")){
        freopen(__file_name ".inp", "r", stdin);
        freopen(__file_name ".out", "w", stdout);
    }
    // code here
    cin >> n >> m >> q;
    st = SegTree(n);
    f1(i,m){
        cin >> a[i].first >> a[i].second;
        upd[a[i].second].push_back(i);
    }
    f1(i,q){
        int l, r; cin >> l >> r;
        qu[r].push_back({l, i});
    }
    f1(r, n){
        for(int idx: upd[r]){
            int l = a[idx].first;
            st.updatePoint(l, Value(l, r));
        }
        for(pair<int,int> qq: qu[r]){
            int l = qq.first, idx = qq.second;
            Value vv = st.getRange(l, r);
            ans[idx] = (vv.le == l && vv.ri == r);
        }
    }
    f1(i,q) cout << (ans[i] ? "YES" : "NO") << '\n';
    return 0;
}

Compilation message (stderr)

curtains.cpp: In function 'int main()':
curtains.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen(__file_name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:70:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |         freopen(__file_name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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