제출 #745808

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
745808		vjudge1	Event Hopping (BOI22_events)	C++17	0 / 100	1080 ms	8152 KiB

events

#include <bits/stdc++.h>

using namespace std;
using ll = long long int;

const ll mod = 1e9 + 7;

int c[100100], hely[100100];

struct P
{
    int poz, id;
    bool veg;
};

bool cmp(P& lhs, P& rhs){
    if(lhs.poz != rhs.poz){
        return lhs.poz < rhs.poz;
    }
    return lhs.veg < rhs.veg;
}

int kov[100100] = {0}, be[100100] = {0};

int main(){
    int n, q;
    cin >> n >> q;
    vector<P> v;
    for(int i = 1; i <= n; ++i){
        int b, e;
        cin >> b >> e;
        v.push_back({b, i, false});
        v.push_back({e, i, true});
    }
    sort(begin(v), end(v), cmp);
    set<int> act;
    for(auto i : v){
        if(i.veg){
            act.erase(i.id);
            kov[i.id] = *act.begin();
            be[*act.begin()]++;
        }
        else{
            act.emplace(i.id);
        }
    }
    int ctr = 0;
    for(int i = 1; i <= n; ++i){
        if(be[i] == 0){
            ++ctr;
            int ptr = i, poz = 1;
            while(ptr != 0){
                c[ptr] = ctr;
                hely[ptr] = poz;
                ++poz;
                ptr = kov[ptr];
            }
        }
    }
    while(q--){
        int a, b;
        cin >> a >> b;
        if(c[a] != c[b] || hely[a] > hely[b]){
            cout << "impossible" << endl;
        }
        else{
            cout << hely[b] - hely[a] << endl;
        }
    }
    return 0;
}

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