Submission #587611

#	Time	Username	Problem	Language	Result	Execution time	Memory
587611		cfalas	Event Hopping (BOI22_events)	C++17	10 / 100	1593 ms	42440 KiB

events

#include<bits/stdc++.h>
using namespace std;
#define mp make_pair
#define INF 10000000
#define MOD 1000000007
#define MID ((l+r)/2)
#define HASHMOD 2305843009213693951
#define ll long long
#define ull unsigned long long
#define F first
#define S second
typedef pair<ll, ll> ii;
typedef pair<ii, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef map<int, int> mii;

#define EPS 1e-6
#define FOR(i,n) for(int i=0;i<((int)(n));i++)
#define FORi(i,a,b) for(int i=((int)(a));i<((int)(b));i++)
#define FOA(v, a) for(auto v : a)

int t, n;
vi a, b;
vector<vi> adj;
int ans[5500][5500];
int main(){
	int q;
	cin>>n>>q;
	adj.assign(n+1, vi());
	vii e(n);
	FOR(i,n){
		cin>>e[i].F>>e[i].S;
	}
	FOR(i,n){
		FOR(j,n){
			if(i==j) continue;
			if(e[j].F<=e[i].S && e[i].S<=e[j].S){
				adj[i+1].push_back(j+1);
			}
		}
		/*
		cout<<i+1<<": ";
		FOA(v, adj[i+1]) cout<<v<<" ";
		cout<<endl;
		*/
	}
	FORi(i,1,n+1){
		queue<ii> q;
		q.push({0, i});
		FOR(j,n+1) ans[i][j] = MOD;
		ans[i][i] = 0;
		while(!q.empty()){
			ii t = q.front();
			q.pop();

			if(-t.F > ans[i][t.S]) continue;

			FOA(v, adj[t.S]){
				if(ans[i][v] > 1 - t.F){
					ans[i][v] = 1 - t.F;
					q.push({-ans[i][v], v});
				}
			}

		}
	}
	while(q--){
		int a, b;
		cin>>a>>b;
		if(ans[a][b] < MOD) cout<<ans[a][b]<<endl;
		else cout<<"impossible\n";
	}
}

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