oj.uz

Submission #855162

# Submission time Handle Problem Language Result Execution time Memory
855162 2023-09-30T11:08:37 Z Litusiano Event Hopping (BOI22_events) C++17
30 / 100
 236 ms 40124 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);
  if(table[l][k].f == table[r-(1ll<<k)+1][k].f) return max(table[l][k], table[r-(1<<k)+1][k]);
  else 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));
            //if(k < 3) cerr<<"TABLE "<<i<<" "<<x<<" "<<k<<" "<<table[i][k-1].f<<" "<<table[i][k-1].s<<" "<<table[x][k-1].f<<" "<<table[x][k-1].s<<endl;
            if(table[i][k-1].f == table[x][k-1].f) table[i][k] = max(table[i][k-1],table[x][k-1]);
            else table[i][k] = min(table[i][k-1],table[x][k-1]);
 
        }
 
    }
  For(i,n,0){
    int l = 0; int r = n;
    while(r > l+1){
      int m = (l+r)/2;
      //cerr<<v[m].e<<" "<<v[i].s<<endl;
      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;
    else jump[i][0] = n;
  }
  //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];
     if((v[e].e >= v[s].s && v[e].e <= v[s].e)){
        cout<<1<<endl; continue;
    }
    //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(s == e){
      cout<<ans<<endl; continue;
    }
    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 12 ms 23284 KB Output is correct
2 Correct 200 ms 39612 KB Output is correct
3 Correct 199 ms 39200 KB Output is correct
4 Correct 205 ms 39348 KB Output is correct
5 Correct 211 ms 39564 KB Output is correct
6 Correct 207 ms 39456 KB Output is correct
7 Correct 223 ms 39324 KB Output is correct
8 Correct 201 ms 40124 KB Output is correct
9 Correct 195 ms 39736 KB Output is correct
10 Correct 236 ms 39624 KB Output is correct
11 Correct 220 ms 39624 KB Output is correct
12 Correct 188 ms 39924 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23104 KB Output is correct
2 Correct 14 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 13 ms 23256 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 14 ms 23128 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 23104 KB Output is correct
2 Correct 14 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 13 ms 23256 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 14 ms 23128 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 23104 KB Output is correct
2 Correct 14 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 13 ms 23256 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 14 ms 23128 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 198 ms 39284 KB Output is correct
2 Correct 207 ms 39496 KB Output is correct
3 Correct 209 ms 39368 KB Output is correct
4 Correct 195 ms 39876 KB Output is correct
5 Correct 219 ms 39576 KB Output is correct
6 Correct 228 ms 39520 KB Output is correct
7 Correct 233 ms 39724 KB Output is correct
8 Correct 218 ms 39624 KB Output is correct
9 Correct 66 ms 38608 KB Output is correct
10 Correct 200 ms 39392 KB Output is correct
11 Correct 193 ms 38856 KB Output is correct
12 Correct 199 ms 39108 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23284 KB Output is correct
2 Correct 200 ms 39612 KB Output is correct
3 Correct 199 ms 39200 KB Output is correct
4 Correct 205 ms 39348 KB Output is correct
5 Correct 211 ms 39564 KB Output is correct
6 Correct 207 ms 39456 KB Output is correct
7 Correct 223 ms 39324 KB Output is correct
8 Correct 201 ms 40124 KB Output is correct
9 Correct 195 ms 39736 KB Output is correct
10 Correct 236 ms 39624 KB Output is correct
11 Correct 220 ms 39624 KB Output is correct
12 Correct 188 ms 39924 KB Output is correct
13 Correct 13 ms 23104 KB Output is correct
14 Correct 14 ms 23132 KB Output is correct
15 Correct 13 ms 23132 KB Output is correct
16 Correct 13 ms 23256 KB Output is correct
17 Correct 13 ms 23132 KB Output is correct
18 Incorrect 14 ms 23128 KB Output isn't correct
19 Halted 0 ms 0 KB -