Submission #244181

#	Time	Username	Problem	Language	Result	Execution time	Memory
244181		Osama_Alkhodairy	Port Facility (JOI17_port_facility)	C++17	0 / 100	5 ms	384 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long

const int N = 2000001;

int n, tree[4 * N], mod = 1e9 + 7;
vector <int> a;

void update(int l, int r, int node, int idx, int val){
    if(r < l || r < idx || l > idx) return;
    if(l == r){
        tree[node] += val;
        return;
    }
    int mid = (l + r) / 2;
    update(l, mid, 2 * node, idx, val);
    update(mid + 1, r, 2 * node + 1, idx, val);
    tree[node] = max(tree[2 * node], tree[2 * node + 1]);
}
int query(int l, int r, int node, int s, int e){
    if(r < l || r < s || l > e) return -1e9;
    if(s <= l && r <= e) return tree[node];
    int mid = (l + r) / 2;
    return max(query(l, mid, 2 * node, s, e), query(mid + 1, r, 2 * node + 1, s, e));
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n;
    a.resize(2 * n);
    vector <int> l(n + 1), r(n + 1);
    for(int i = 1 ; i <= n ; i++){
        cin >> l[i] >> r[i];
        l[i]--; r[i]--;
        a[l[i]] = i;
        a[r[i]] = -i;
    }
    int ans = 1;
    for(auto &i : a){
        if(i < 0){
            int cur = -i;
            for(int j = l[cur] ; j < r[cur] ; j++){
                if(a[j] > 0 && r[a[j]] > r[cur]){
                    update(0, 2 * n, 1, r[a[j]], -1);
                }
            }
            continue;
        }
        int b = query(0, 2 * n, 1, l[i], r[i]);
        if(b >= 2) finish(0);
        else if(b == 0){
            ans *= 2;
            if(ans >= mod) ans -= mod;
        }
        update(0, 2 * n, 1, r[i], b + 1);
    }
    cout << ans << endl;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22