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Submission #855140

# Submission time Handle Problem Language Result Execution time Memory
855140 2023-09-30T10:03:18 Z Litusiano Event Hopping (BOI22_events) C++14
30 / 100
 262 ms 40140 KB 
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;

//#define int long long
#define f first
#define s second
#define ii pair<int,int>
#define vi vector<int>
#define vvi vector<vi>
#define vvii vector<vector<ii>>
#define pb push_back
#define vpi vector<ii> 
#define forcin for(int i = 0; i<n; ++i) cin>>v[i];
#define ld long double
#define all(a) (a).begin(),(a).end()
#define For(i, n, x) for (int i = x; i < n; i++)
#define rsz(a,x) assign(a,x)
const int MAXN = 1e5+5;
vvii table(MAXN,vpi(25,{0,0}));
struct Segment{
  int s,e,idx;
};

 
ii query(int l,int r){
 
  int len = r-l+1;
  int k = 31- __builtin_clz(len);
  return min(table[l][k], table[r-(1<<k)+1][k]);
}
 


bool cmp(Segment a, Segment b){
  if(a.e == b.e) return a.s > b.s;
  return a.e > b.e;
}

signed main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n,q; cin>>n>>q;
  vector<Segment> v(n);
  vpi start;
  For(i,n,0){
    int s,e; cin>>s>>e;
    v[i].s = s; v[i].e = e; v[i].idx = i;
    start.pb({e,i});
  }
  sort(all(v),cmp);
  vi idxs(n+1);
  vvi jump(n+1,vi(25,n));  
  For(i,n,0) table[i][0] = {v[i].s,i};
    For(k,25,1){
        for(int i = 0; i+ (1<<k) -1< n; i++){
            int x = i+(1<<(k-1));
            table[i][k] = min(table[i][k-1],table[x][k-1]);
 
        }
 
    }
  For(i,n,0){
    int l = 0; int r = n+1;
    while(r > l+1){
      int m = (l+r)/2;
      if(v[m].e >= v[i].s) l = m;
      else r = m;
    }
    int idx = l;
    //cerr<<i<<" "<<idx<<" "<<S.s<<" "<<S.e<<" "<<S.idx<<" "<<v[idx].s<<" "<<v[idx].e<<" "<<v[idx].idx<<endl;
    /*if(idx == i){
      jump[v[i].idx][0] = 0; continue;
    }*/
    //cerr<<"IDX "<<idx<<" "<<i<<endl;
    if(i >= idx) {
      jump[i][0] = n; continue;
    }
    ii p = query(i,idx);
    //cerr<<"IDX "<<v[i].s<<" "<<v[i].e<<" "<<idx<<" "<<i<<" "<<p.f<<" "<<p.s<<endl;
    if(p.s == i){
      p = query(i+1,idx);
    }
    if(p.s != i) jump[i][0] = p.s;
  }
  //Build Binary Lifting
  For(k,25,1){
    For(i,n,0){
      jump[i][k] = jump[jump[i][k-1]][k-1];
      if(jump[i][k] == i || jump[i][k] == jump[i][k-1]) jump[i][k] = n;
    }
  }
  For(i,n,0) idxs[v[i].idx] = i;
  /*For(i,n,0){
    cerr<<i<<" "<<v[i].s<<" "<<v[i].e<<" "<<v[i].idx<<endl;
    cerr<<jump[i][0]<<" "<<jump[i][1]<<" "<<jump[i][2]<<endl<<endl;
  }*/
  while(q--){
    int s,e; cin>>s>>e; s--,e--; swap(s,e);
    if(s == e){
      cout<<0<<endl; continue;
    }
    s = idxs[s]; e = idxs[e];
    //cerr<<s<<" "<<e<<endl;
    int ans = 0;
    for(int i = 24; i>=0; i--){
      if(jump[s][i] < e){
        s = jump[s][i];
        ans+=(1ll<<i);
      }
    }
    //cerr<<"ANS "<<s<<" "<<jump[s][0]<<" "<<e<<" "<<v[e].s<<" "<<v[s].e<<" "<<v[e].e<<endl;
    if(!(v[e].e >= v[s].s && v[e].e <= v[s].e)) cout<<"impossible"<<endl;
    else cout<<ans+1<<endl;
  }

}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23132 KB Output is correct
2 Correct 200 ms 39332 KB Output is correct
3 Correct 211 ms 39340 KB Output is correct
4 Correct 216 ms 39224 KB Output is correct
5 Correct 204 ms 39364 KB Output is correct
6 Correct 221 ms 39368 KB Output is correct
7 Correct 207 ms 39448 KB Output is correct
8 Correct 211 ms 40140 KB Output is correct
9 Correct 196 ms 39944 KB Output is correct
10 Correct 258 ms 39928 KB Output is correct
11 Correct 262 ms 39592 KB Output is correct
12 Correct 186 ms 39788 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23128 KB Output is correct
2 Correct 12 ms 23132 KB Output is correct
3 Correct 13 ms 23128 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23288 KB Output is correct
6 Incorrect 14 ms 23132 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23128 KB Output is correct
2 Correct 12 ms 23132 KB Output is correct
3 Correct 13 ms 23128 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23288 KB Output is correct
6 Incorrect 14 ms 23132 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23128 KB Output is correct
2 Correct 12 ms 23132 KB Output is correct
3 Correct 13 ms 23128 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23288 KB Output is correct
6 Incorrect 14 ms 23132 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 200 ms 39324 KB Output is correct
2 Correct 206 ms 39272 KB Output is correct
3 Correct 237 ms 39364 KB Output is correct
4 Correct 206 ms 39848 KB Output is correct
5 Correct 249 ms 39912 KB Output is correct
6 Correct 227 ms 39336 KB Output is correct
7 Correct 228 ms 39556 KB Output is correct
8 Correct 223 ms 39684 KB Output is correct
9 Correct 67 ms 38808 KB Output is correct
10 Correct 208 ms 39072 KB Output is correct
11 Correct 201 ms 38852 KB Output is correct
12 Correct 201 ms 39148 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23132 KB Output is correct
2 Correct 200 ms 39332 KB Output is correct
3 Correct 211 ms 39340 KB Output is correct
4 Correct 216 ms 39224 KB Output is correct
5 Correct 204 ms 39364 KB Output is correct
6 Correct 221 ms 39368 KB Output is correct
7 Correct 207 ms 39448 KB Output is correct
8 Correct 211 ms 40140 KB Output is correct
9 Correct 196 ms 39944 KB Output is correct
10 Correct 258 ms 39928 KB Output is correct
11 Correct 262 ms 39592 KB Output is correct
12 Correct 186 ms 39788 KB Output is correct
13 Correct 13 ms 23128 KB Output is correct
14 Correct 12 ms 23132 KB Output is correct
15 Correct 13 ms 23128 KB Output is correct
16 Correct 14 ms 23132 KB Output is correct
17 Correct 13 ms 23288 KB Output is correct
18 Incorrect 14 ms 23132 KB Output isn't correct
19 Halted 0 ms 0 KB -