Submission #1135778

#	Time	Username	Problem	Language	Result	Execution time	Memory
1135778		Zbyszek99	Event Hopping (BOI22_events)	C++20	0 / 100	155 ms	22672 KiB

events

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

const int tree_siz = (1 << 19)-1;
pii drzewo[tree_siz];
int jump[100'001][18];
pii seg[100'001];
int max_end[100'001];

pii get_min(int akt, int p1, int p2, int s1, int s2)
{
    if(p2 < s1 || p1 > s2) return {1e9,-1};
    if(p1 >= s1 && p2 <= s2) return drzewo[akt-1];
    return min(get_min(akt*2,p1,(p1+p2)/2,s1,s2),get_min(akt*2+1,(p1+p2)/2+1,p2,s1,s2));
}

void upd(int v)
{
    drzewo[v-1] = min(drzewo[v*2-1],drzewo[v*2]);
    if(v != 1) upd(v/2);
}

void change(int ind, pii w)
{
    drzewo[tree_siz/2+ind] = min(w,drzewo[tree_siz/2+ind]);
    upd((tree_siz/2+ind+1)/2);
}


int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n,q;
    cin >> n >> q;
    rep(i,tree_siz) drzewo[i] = {1e9,-1};
    map<int,int> m;
    vector<pair<int,pii>> events;
    rep(i,n)
    {
        int a,b;
        cin >> a >> b;
        m[a]++;
        m[b]++;
        seg[i] = {a,b};
    }
    int cur = 0;
    forall(it,m)
    {
        m[it.ff] = cur++;
    }
    rep(i,n)
    {
        seg[i].ff = m[seg[i].ff];
        seg[i].ss = m[seg[i].ss];
        //cout << seg[i].ff << " " << seg[i].ss << " seg\n";
        change(seg[i].ss,{seg[i].ff,i});
    }
    rep(i,n)
    {
        pii nxt = get_min(1,0,tree_siz/2,seg[i].ff,seg[i].ss);
        jump[i][0] = nxt.ss;
       // cout << nxt.ss << " nxt\n";
    }
    rep2(bit,1,17)
    {
        rep(i,n)
        {
            jump[i][bit] = jump[jump[i][bit-1]][bit-1];
        }
    }
    rep(qq,q)
    {
        int s,e;
        cin >> s >> e;
        s--;
        e--;
        //cout << seg[jump[e][17]].ff << " p\n";
        if(seg[jump[e][17]].ff > seg[s].ss || seg[s].ss > seg[e].ss)
        {
            cout << "impossible\n";
            continue;
        }
        if(seg[s].ss >= seg[e].ff)
        {
            cout << "1\n";
            continue;
        }
        if(s == e)
        {
            cout << "0\n";
            continue;
        }
        int ans = 0;
        for(int bit = 16; bit >= 0; bit--)
        {
            if(seg[jump[e][bit]].ff > seg[s].ss)
            {
                ans += (1 << bit);
                e = jump[e][bit];
            }
           // cout << e << " " << jump[e][bit] << " e\n";
        }
        cout << ans +2 << "\n";
    }
}

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