Submission #869691

#	Time	Username	Problem	Language	Result	Execution time	Memory
869691		Ahmed_Solyman	Event Hopping (BOI22_events)	C++14	0 / 100	1583 ms	192156 KiB

events

/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
#include <ext/rope>
 
using namespace std;
using namespace __gnu_cxx;
#pragma GCC optimize("-Ofast")
#pragma GCC optimize("-O1")
//-------------------------------------------------------------//
typedef long long ll;
typedef unsigned long long ull;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define PI acos(-1)
#define lb lower_bound
#define ub upper_bound
#define endl '\n'
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sum_to(n) (n*(n+1))/2
#define pb push_back
#define pf push_front
#define fil(arr,x) memset(arr,x,sizeof(arr))
const ll mod=1e9+7;
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
//-------------------------------------------------------------//
ll lcm(ll a,ll b)
{
    return (max(a,b)/__gcd(a,b))*min(a,b);
}
void person_bool(bool x)
{
    cout<<(x?"YES":"NO")<<endl;
}
const int N=5005;
int dist[N][N],head[N*N],t[N*N],nxt[N*N],ne=0;
void addEdge(int u,int v){
	t[ne]=v;
	nxt[ne]=head[u];
	head[u]=ne++;
}
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    #ifndef ONLINE_JUDGE
    //freopen("input.in", "r", stdin);
    //freopen("output.out", "w", stdout);
    #endif
    fast
    int n,m;cin>>n>>m;
    vector<int>l(n+5),r(n+5);
    for(int i=1;i<=n;i++){
    	cin>>l[i]>>r[i];
    }
    fil(head,-1);
    for(int i=1;i<=n;i++){
    	for(int j=1;j<=n;j++){
    		if(i==j)continue;
    		dist[i][j]=1e9;
    		if(r[i]>=l[j] && r[i]<=r[j]){
    			addEdge(i,j);
    		}
    	}
    }
    queue<int>q;
    for(int i=1;i<=n;i++){
    	q.push(i);
    	while(q.size()){
    		int x=q.front();
    		q.pop();
    		for(int j=head[x];~j;j=nxt[j]){
    		    if(dist[i][t[j]]>dist[i][x]+1){
    				dist[i][t[j]]=dist[i][x]+1;
    				q.push(t[j]);
    			}
    		}
    	}
    }
    while(m--){
    	int a,b;cin>>a>>b;
    	if(dist[a][b]==1e9)cout<<"impossible"<<endl;
    	else cout<<dist[a][b]<<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