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Submission #734982

# Submission time Handle Problem Language Result Execution time Memory
734982 2023-05-03T10:37:09 Z Victor Event Hopping (BOI22_events) C++17
45 / 100
 469 ms 67496 KB 
// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (ll i = (a); i < (b); ++i)
#define per(i, a, b) for (ll i = (b) - 1; i >= (a); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) (ll)x.size()
#define pb push_back
#define mp make_pair
#define debug(x) cout<<#x<<" = "<<x<<endl

#define umap unordered_map
#define uset unordered_set

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;

typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<ll,pll> ppll;
typedef vector<ll> vll;
typedef vector<pll> vpll;

const ll INF = 1'000'000'007;

struct Node {
    ll lo,hi,val=INF,id=INF;
    Node *l,*r;

    Node(ll L,ll R) : lo(L),hi(R) {
        if(hi-lo!=1) {
            ll mid=(lo+hi)/2;
            l=new Node(lo,mid);
            r=new Node(mid,hi);
        }
    }

    pll query(ll L,ll R) {
        if(R<=lo||hi<=L) return {INF,INF};
        if(L<=lo&&hi<=R) return {val,id};
        return min(l->query(L,R),r->query(L,R));
    }

    void update(ll pos,ll x,ll nid) {
        if(pos<lo||hi<=pos) return;
        if(hi-lo==1) {
            if(x<val) {
                val=x;
                id=nid;
            }
            return;
        }

        l->update(pos,x,nid);
        r->update(pos,x,nid);
        tie(val,id)=min(pll(l->val,l->id),pll(r->val,r->id));
    }
};

ll n,q,jmp[20][100005];
vector<pair<pll,ll>> sorted_events;
vpll events;

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);


    cin>>n>>q;
    rep(i,0,n+1) jmp[0][i]=n;

    set<ll> coords;
    umap<ll,ll>compress;

    rep(i,0,n) {
        ll s,e;
        cin>>s>>e;
        events.emplace_back(s,e);
        coords.insert(s);
        coords.insert(e);
    }

    {
        ll cnt=0;
        trav(val,coords) compress[val]=cnt++;
        rep(i,0,n) {
            events[i].first=compress[events[i].first];
            events[i].second=compress[events[i].second];
            sorted_events.emplace_back(events[i],i);
        }
    }

    sort(all(sorted_events));
    Node segtree(0,2*n+1);

    trav(event,sorted_events) {
        ll s,e,id=event.second;
        tie(s,e)=event.first;

        pll best=segtree.query(s,e+1);
        if(best.first!=INF) jmp[0][id]=best.second;
        segtree.update(e,s,id);
    }

    rep(j,1,20) rep(i,0,n+1) jmp[j][i]=jmp[j-1][jmp[j-1][i]]; 

    while(q--) {
        ll a,b;
        cin>>a>>b;
        --a; --b;

        if(events[a].second>events[b].second) {
            cout<<"impossible"<<endl;
            continue;

        } else if(a==b) {
            cout<<0<<endl;
            continue;
        }

        ll ans=0;

        per(j,0,20) {
            ll nxt=jmp[j][b];
            if(nxt==n||events[nxt].first<=events[a].second) continue;
            b=nxt;
            ans+=1<<j;
        }

        ll nxt=jmp[0][b];
        if(nxt==n) {
            cout<<"impossible"<<endl;
            continue;
        }

        // cout<<"a = "<<events[a].first<<' '<<events[a].second<<endl;
        // cout<<"b = "<<events[nxt].first<<' '<<events[nxt].second<<endl;
        ++ans;
        if(events[a].second<events[b].first) ++ans;
        cout<<ans<<endl;
    }

    _Exit(0);
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 293 ms 57744 KB Output is correct
3 Correct 293 ms 57816 KB Output is correct
4 Correct 393 ms 57820 KB Output is correct
5 Correct 310 ms 58632 KB Output is correct
6 Correct 339 ms 59312 KB Output is correct
7 Correct 314 ms 59572 KB Output is correct
8 Incorrect 335 ms 67492 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 980 KB Output is correct
4 Correct 2 ms 976 KB Output is correct
5 Correct 2 ms 980 KB Output is correct
6 Correct 2 ms 980 KB Output is correct
7 Correct 2 ms 980 KB Output is correct
8 Correct 2 ms 984 KB Output is correct
9 Correct 2 ms 852 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 980 KB Output is correct
4 Correct 2 ms 976 KB Output is correct
5 Correct 2 ms 980 KB Output is correct
6 Correct 2 ms 980 KB Output is correct
7 Correct 2 ms 980 KB Output is correct
8 Correct 2 ms 984 KB Output is correct
9 Correct 2 ms 852 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 2 ms 980 KB Output is correct
13 Correct 2 ms 916 KB Output is correct
14 Correct 2 ms 980 KB Output is correct
15 Correct 2 ms 916 KB Output is correct
16 Correct 2 ms 980 KB Output is correct
17 Correct 2 ms 980 KB Output is correct
18 Correct 2 ms 856 KB Output is correct
19 Correct 155 ms 4656 KB Output is correct
20 Correct 145 ms 4588 KB Output is correct
21 Correct 147 ms 4756 KB Output is correct
22 Correct 151 ms 4992 KB Output is correct
23 Incorrect 138 ms 5156 KB Output isn't correct
24 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 980 KB Output is correct
4 Correct 2 ms 976 KB Output is correct
5 Correct 2 ms 980 KB Output is correct
6 Correct 2 ms 980 KB Output is correct
7 Correct 2 ms 980 KB Output is correct
8 Correct 2 ms 984 KB Output is correct
9 Correct 2 ms 852 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 2 ms 912 KB Output is correct
13 Correct 2 ms 980 KB Output is correct
14 Correct 2 ms 980 KB Output is correct
15 Correct 2 ms 984 KB Output is correct
16 Correct 3 ms 980 KB Output is correct
17 Correct 2 ms 980 KB Output is correct
18 Correct 2 ms 852 KB Output is correct
19 Correct 131 ms 56032 KB Output is correct
20 Correct 122 ms 55200 KB Output is correct
21 Correct 156 ms 55980 KB Output is correct
22 Correct 178 ms 58900 KB Output is correct
23 Correct 228 ms 65288 KB Output is correct
24 Correct 208 ms 65252 KB Output is correct
25 Correct 84 ms 46188 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 262 ms 57804 KB Output is correct
2 Correct 298 ms 57772 KB Output is correct
3 Correct 359 ms 57952 KB Output is correct
4 Correct 354 ms 67496 KB Output is correct
5 Correct 349 ms 58328 KB Output is correct
6 Correct 409 ms 67096 KB Output is correct
7 Correct 469 ms 67060 KB Output is correct
8 Correct 420 ms 67300 KB Output is correct
9 Correct 214 ms 65272 KB Output is correct
10 Correct 372 ms 66820 KB Output is correct
11 Correct 374 ms 66528 KB Output is correct
12 Correct 379 ms 66740 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 293 ms 57744 KB Output is correct
3 Correct 293 ms 57816 KB Output is correct
4 Correct 393 ms 57820 KB Output is correct
5 Correct 310 ms 58632 KB Output is correct
6 Correct 339 ms 59312 KB Output is correct
7 Correct 314 ms 59572 KB Output is correct
8 Incorrect 335 ms 67492 KB Output isn't correct
9 Halted 0 ms 0 KB -