Submission #714320

#	Time	Username	Problem	Language	Result	Execution time	Memory
714320		Khizri	Event Hopping (BOI22_events)	C++17	10 / 100	1583 ms	199564 KiB

events

#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
using namespace std;
//------------------------------DEFINE------------------------------
//******************************************************************
#define IOS ios_base::sync_with_stdio(false); cin.tie(0),cout.tie(0)
#define ll long long
#define pb push_back
#define F first
#define S second
#define INF 1e18
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define OK cout<<"Ok"<<endl;
#define MOD (ll)(1e9+7)
#define endl "\n"
//******************************************************************
//----------------------------FUNCTION------------------------------
//******************************************************************
ll gcd(ll a,ll b){
    if(a>b) swap(a,b);
    if(a==0) return a+b;
    return gcd(b%a,a);
}
ll lcm(ll a,ll b){
    return a/gcd(a,b)*b;
}
bool is_prime(ll n){
    ll k=sqrt(n);

    if(n==2) return true;
    if(n<2||n%2==0||k*k==n) return false;
    for(int i=3;i<=k;i+=2){
        if(n%i==0){
            return false;
        }
    }
    return true;
}
//*****************************************************************
//--------------------------MAIN-CODE------------------------------
const int mxn=5e3+5;
int t=1,n,m,x[mxn],y[mxn],dis[mxn][mxn];
vector<int>vt[mxn];
void bfs(int k){
    queue<int>q;
    q.push(k);
    dis[k][k]=0;
    while(q.size()>0){
        int u=q.front();
        q.pop();
        for(int v:vt[u]){
            if(dis[k][v]==-1){
                dis[k][v]=dis[k][u]+1;
                q.push(v);
            }
        }
    }
}
void solve(){
    memset(dis,-1,sizeof(dis));
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>x[i]>>y[i];
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(x[j]<=y[i]&&y[i]<=y[j]){
                vt[i].pb(j);
            }
        }
    }
    for(int i=1;i<=n;i++){
        bfs(i);
    }
    while(m--){
        int a,b;
        cin>>a>>b;
        if(dis[a][b]==-1){
            cout<<"impossible"<<endl;
        }
        else{
            cout<<dis[a][b]<<endl;
        }
    }
}
int main(){
    IOS;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

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