Submission #1127912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127912		pemguimn	Curtains (NOI23_curtains)	C++17	100 / 100	929 ms	108204 KiB

curtains

#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;

const int N = 1e6 + 5;

struct node{
    int x, lz;

     node(){
        x = lz = -1;
     }
};

node unite(const node &x, const node &y){
    node ans;
    ans.x = min(x.x, y.x);
    return ans;
}

struct SegmentTree{
    vector<node> seg; int n;

    void init(int _n){
        n = _n; seg.resize(4 * n + 5);
    }

    void apply(int id, int x){
        seg[id].x = max(seg[id].x, x);
        seg[id].lz = max(seg[id].lz, x);
    }

    void down(int id){
        int &t = seg[id].lz;
        apply(id * 2, t), apply(id * 2 + 1, t);
        t = -1;
    }

    void upd(int id, int tl, int tr, int l, int r, int x){
        if(r < tl || tr < l) return;
        if(l <= tl && tr <= r){
            apply(id, x); return;
        }
        int mid = (tl + tr) / 2; down(id);
        upd(id * 2, tl, mid, l, r, x), upd(id * 2 + 1, mid + 1, tr, l, r, x);
        seg[id] = unite(seg[id * 2], seg[id * 2 + 1]);
    }

    int query(int id, int tl, int tr, int l, int r){
        if(r < tl || tr < l) return N;
        if(l <= tl && tr <= r) return seg[id].x;
        int mid = (tl + tr) / 2; down(id);
        return min(query(id * 2, tl, mid, l, r), query(id * 2 + 1, mid + 1, tr, l, r));
    }
};

int n, m, q, l[N], r[N], s[N], e[N];
bool ans[N];

vector<int> upd[N];
vector<pii> qq[N];

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

//    #define task "noicurtains"
//    if(fopen(task".inp", "r")){
//        freopen(task".inp", "r", stdin);
//        freopen(task".out", "w", stdout);
//    }
    cin >> n >> m >> q;
    for(int i = 1; i <= m; i++){
        cin >> l[i] >> r[i];
        upd[r[i]].push_back(l[i]);
    }
    for(int i = 1; i <= q; i++){
        cin >> s[i] >> e[i];
        qq[e[i]].push_back({s[i], i});
    }

    SegmentTree a; a.init(n + 1);

    for(int i = 1; i <= n; i++){
        for(int x : upd[i]) a.upd(1, 1, n, x, i, x);
        for(pii qu : qq[i]){
            if(a.query(1, 1, n, qu.first, i) == qu.first) ans[qu.second] = 1;
        }
    }
    for(int i = 1; i <= q; i++)
        cout << (ans[i] ? "YES" : "NO") << "\n";
    return 0;
}

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