제출 #993012

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
993012		amine_aroua	Event Hopping (BOI22_events)	C++17	0 / 100	472 ms	119132 KiB

events

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define nl '\n'
#define pb push_back
#define fore(i , n) for(int i = 0 ; i< n;i++)
#define forr(i , x , y) for(int i = x; i <= y; i++)
#define forn(i , x , y) for(int i = x; i >= y ; i--)
const int N =2e5 + 10;
struct seg
{
    int BASE;
    vector<int> tree;
    void init(int n , vector<int> &a)
    {
        BASE = n;
        while(__builtin_popcount(BASE) != 1)
        {
            BASE++;
        }
        tree.assign(2*BASE , 0);
        fore(i  , (int)a.size())
            tree[i + BASE] = a[i];
        forn(i  , BASE - 1 , 1)
            tree[i] = max(tree[2*i] , tree[2*i +1]);
    }
    int query(int l , int r)
    {
        if(l > r)
            return 0;
        l+=BASE;
        r+=BASE;
        if(l == r)
            return tree[l];
        int lt = tree[l] , rt = tree[r];
        while(l + 1 < r)
        {
            if(l %2 == 0)
            {
                lt = max(lt , tree[l +1]);
            }
            if(r%2 == 1)
                rt = max(tree[r - 1] ,rt);
            l>>=1;
            r>>=1;
        }
        return max(lt ,rt);
    }
}tree[19];
signed main()
{
    int n , q;
    cin>>n>>q;
    map<int , int> compress;
    vector<pair<int ,int>> v(n);
    vector<vector<int>> adj(20 , vector<int>(N));
    vector<tuple<int , int, int>> koll;
    fore(i , n)
    {
        cin>>v[i].first>>v[i].second;
        koll.pb({v[i].first , 0 , i});
        koll.pb({v[i].second , 1 , i});
    }
    vector<pair<int ,int>> iv = v;
    sort(koll.begin() , koll.end());
    int cnt = 0;
    for(auto [x , t , i] : koll)
    {
        if(t == 0)
            v[i].first = cnt++;
        else
            v[i].second = cnt++;
    }
    fore(i , n)
    {
        adj[0][v[i].first] = v[i].second;
    }
    forr(i , 1 , 19)
    {
        tree[i - 1].init(N , adj[i - 1]);
        fore(j , N)
        {
            adj[i][j] = tree[i - 1].query(j , adj[i - 1][j]);
        }
    }
    while(q--)
    {
        int s , e;
        cin>>s>>e;
        s-- , e--;
        if(v[s].second > v[e].second)
        {
            cout<<"impossible"<<nl;
            continue;
        }
        if(v[e].first <= v[s].first && v[s].second <= v[e].second)
        {
            cout<<1<<nl;
            continue;
        }
        int cur = v[s].first;
        s = v[s].first;
        e = v[e].second;
        int ans = 0;
        forn(i , 18 , 0)
        {
            int ns = tree[i].query(s , cur);
            if(ns >= e)
                continue;
            cur = ns;
            ans+=(1<<i);
        }
        if(ans >= (1<<17))
            cout<<"impossible"<<nl;
        else
            cout<<ans<<nl;
    }
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30