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Submission #853473

# Submission time Handle Problem Language Result Execution time Memory
853473 2023-09-24T12:04:12 Z vjudge1 Event Hopping (BOI22_events) C++17
30 / 100
 244 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 max(table[l][k], table[r-(1<<k)+1][k]);
}
 

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

bool cmp1(Segment a, Segment b){
  if(a.s == b.s) return a.e > b.e;
  return a.s < b.s;
}

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({s,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].e,i};
    For(k,25,1){
        for(int i = 0; i+ (1<<k) -1< n; i++){
            int x = i+(1<<(k-1));
            if(table[i][k-1].f == table[x][k-1].f) table[i][k] = min(table[i][k-1],table[x][k-1]);
            else table[i][k] = max(table[i][k-1],table[x][k-1]);
 
        }
 
    }
  For(i,n,0){
    
    Segment S; S.s = v[i].e; S.e = 1e9; S.idx = 1e9;
    int idx = (upper_bound(all(v),S,cmp) - v.begin());
    idx--;
    //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;
    }*/
    ii p = query(0,idx);
    if(p.s == i || p.f == v[i].e) jump[i][0] = n; 
    else 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--;s = idxs[s]; e = idxs[e];
    if(s == e){
      cout<<0<<endl; continue;
    }
    //cerr<<s<<" "<<e<<" ";
    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<<endl;
    if(max(e,s) >= n) cout<<"impossible"<<endl;
    else if(!(v[e].s <= v[s].e && v[s].e <= v[e].e)) cout<<"impossible"<<endl;
    else cout<<ans+1<<endl;
  }

}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23128 KB Output is correct
2 Correct 209 ms 39456 KB Output is correct
3 Correct 202 ms 39324 KB Output is correct
4 Correct 209 ms 39620 KB Output is correct
5 Correct 211 ms 39320 KB Output is correct
6 Correct 216 ms 39620 KB Output is correct
7 Correct 207 ms 39364 KB Output is correct
8 Correct 212 ms 39924 KB Output is correct
9 Correct 195 ms 39876 KB Output is correct
10 Correct 241 ms 39620 KB Output is correct
11 Correct 244 ms 39584 KB Output is correct
12 Correct 196 ms 39876 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23128 KB Output is correct
2 Correct 14 ms 23080 KB Output is correct
3 Correct 14 ms 23384 KB Output is correct
4 Correct 16 ms 23128 KB Output is correct
5 Incorrect 14 ms 23128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23128 KB Output is correct
2 Correct 14 ms 23080 KB Output is correct
3 Correct 14 ms 23384 KB Output is correct
4 Correct 16 ms 23128 KB Output is correct
5 Incorrect 14 ms 23128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23128 KB Output is correct
2 Correct 14 ms 23080 KB Output is correct
3 Correct 14 ms 23384 KB Output is correct
4 Correct 16 ms 23128 KB Output is correct
5 Incorrect 14 ms 23128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 204 ms 39364 KB Output is correct
2 Correct 210 ms 39292 KB Output is correct
3 Correct 206 ms 39364 KB Output is correct
4 Correct 202 ms 40140 KB Output is correct
5 Correct 233 ms 39896 KB Output is correct
6 Correct 244 ms 39548 KB Output is correct
7 Correct 241 ms 39364 KB Output is correct
8 Correct 223 ms 39596 KB Output is correct
9 Correct 68 ms 38596 KB Output is correct
10 Correct 205 ms 39108 KB Output is correct
11 Correct 199 ms 38892 KB Output is correct
12 Correct 200 ms 39108 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23128 KB Output is correct
2 Correct 209 ms 39456 KB Output is correct
3 Correct 202 ms 39324 KB Output is correct
4 Correct 209 ms 39620 KB Output is correct
5 Correct 211 ms 39320 KB Output is correct
6 Correct 216 ms 39620 KB Output is correct
7 Correct 207 ms 39364 KB Output is correct
8 Correct 212 ms 39924 KB Output is correct
9 Correct 195 ms 39876 KB Output is correct
10 Correct 241 ms 39620 KB Output is correct
11 Correct 244 ms 39584 KB Output is correct
12 Correct 196 ms 39876 KB Output is correct
13 Correct 14 ms 23128 KB Output is correct
14 Correct 14 ms 23080 KB Output is correct
15 Correct 14 ms 23384 KB Output is correct
16 Correct 16 ms 23128 KB Output is correct
17 Incorrect 14 ms 23128 KB Output isn't correct
18 Halted 0 ms 0 KB -