oj.uz

답안 #855143

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
855143 2023-09-30T10:04:53 Z Litusiano Event Hopping (BOI22_events) C++17
30 / 100
 240 ms 40008 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;
    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];
    //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

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23132 KB Output is correct
2 Correct 200 ms 39272 KB Output is correct
3 Correct 197 ms 39336 KB Output is correct
4 Correct 207 ms 39368 KB Output is correct
5 Correct 208 ms 39368 KB Output is correct
6 Correct 212 ms 39620 KB Output is correct
7 Correct 208 ms 39320 KB Output is correct
8 Correct 200 ms 39864 KB Output is correct
9 Correct 200 ms 39876 KB Output is correct
10 Correct 227 ms 39608 KB Output is correct
11 Correct 225 ms 39600 KB Output is correct
12 Correct 191 ms 39812 KB Output is correct

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23128 KB Output is correct
2 Correct 13 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 13 ms 23128 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23128 KB Output is correct
2 Correct 13 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 13 ms 23128 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23128 KB Output is correct
2 Correct 13 ms 23132 KB Output is correct
3 Correct 13 ms 23132 KB Output is correct
4 Correct 14 ms 23132 KB Output is correct
5 Correct 13 ms 23132 KB Output is correct
6 Incorrect 13 ms 23128 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 200 ms 39324 KB Output is correct
2 Correct 196 ms 39380 KB Output is correct
3 Correct 213 ms 39732 KB Output is correct
4 Correct 199 ms 40008 KB Output is correct
5 Correct 240 ms 39584 KB Output is correct
6 Correct 233 ms 39400 KB Output is correct
7 Correct 239 ms 39476 KB Output is correct
8 Correct 214 ms 39700 KB Output is correct
9 Correct 66 ms 38600 KB Output is correct
10 Correct 197 ms 39060 KB Output is correct
11 Correct 192 ms 38856 KB Output is correct
12 Correct 198 ms 39076 KB Output is correct

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23132 KB Output is correct
2 Correct 200 ms 39272 KB Output is correct
3 Correct 197 ms 39336 KB Output is correct
4 Correct 207 ms 39368 KB Output is correct
5 Correct 208 ms 39368 KB Output is correct
6 Correct 212 ms 39620 KB Output is correct
7 Correct 208 ms 39320 KB Output is correct
8 Correct 200 ms 39864 KB Output is correct
9 Correct 200 ms 39876 KB Output is correct
10 Correct 227 ms 39608 KB Output is correct
11 Correct 225 ms 39600 KB Output is correct
12 Correct 191 ms 39812 KB Output is correct
13 Correct 12 ms 23128 KB Output is correct
14 Correct 13 ms 23132 KB Output is correct
15 Correct 13 ms 23132 KB Output is correct
16 Correct 14 ms 23132 KB Output is correct
17 Correct 13 ms 23132 KB Output is correct
18 Incorrect 13 ms 23128 KB Output isn't correct
19 Halted 0 ms 0 KB -