Submission #572927

#	Time	Username	Problem	Language	Result	Execution time	Memory
572927		MohamedAliSaidane	Event Hopping (BOI22_events)	C++14	10 / 100	1595 ms	128512 KiB

events

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

        using namespace __gnu_pbds;
        using namespace std;

        typedef tree<int,null_type,less<int>,rb_tree_tag,
        tree_order_statistics_node_update> indexed_set;

        typedef long long ll;
        typedef long double ld;

        typedef pair<int,int> pii;
        typedef pair<ll,ll> pll;
        typedef pair<ld,ld> pld;

        typedef vector<int> vi;
        typedef vector<ll> vll;
        typedef vector<pii> vpi;
        typedef vector<pll> vpl;

        #define pb push_back
        #define popb pop_back
        #define pp pop_back
        #define pf push_front
        #define popf pop_front
        #define all(x) (x).begin(),(x).end()
        #define ff first
        #define ss second

        ///#define int ll

        int nx[4] = {0,0,1,-1}, ny[4] = {1,-1,0,0};
        ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;}
        ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);}

        const int nax = 5001;
        int n, q;
        indexed_set nid;
        vpi v;
        int reach[nax][nax];
        vi adj[nax];
        void solve()
        {
            memset(reach,-1,sizeof(reach));
            cin >> n >> q;
            for(int i = 0; i < n ;i ++)
            {
                int s, e;
                cin >> s >> e;
                nid.insert(s);
                nid.insert(e);
                v.pb({s,e});
            }
            //sort(all(v));
            for(int i = 0; i < n ;i ++)
            {
                for(int j = 0; j < n; j ++)
                {
                    if(v[i].ss >= v[j].ff && v[i].ss <= v[j].ss)
                        adj[i].pb(j);
                }
            }
            for(int i=  0; i < n; i ++)
            {
                queue<pii> q;
                q.push({i,0});
                while(!q.empty())
                {
                    int node = q.front().ff;
                    int d=  q.front().ss;
                    q.pop();
                    reach[i][node] =d;
                    for(auto e: adj[node])
                    {
                        if(reach[i][e] != -1)
                            continue;
                        reach[i][e] = d+ 1;
                        q.push({e,d + 1});
                    }
                }
            }
            while(q--)
            {
                int s, e;
                cin >> s >> e;
                s--; e--;
                if(reach[s][e] == -1)
                    cout << "impossible\n";
                else
                    cout << reach[s][e] << '\n';
            }
        }

        int32_t main()
        {
            ios::sync_with_stdio(false);
            cin.tie(0); cout.tie(0);
            int tt = 1;
            while(tt --)
                solve();
        }

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