oj.uz

답안 #855139

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
855139 2023-09-30T10:01:49 Z Litusiano Event Hopping (BOI22_events) C++17
30 / 100
 255 ms 40392 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){
    Segment S; S.s = v[i].s; S.e = 1e9; S.idx = 1e9;
    int l = 0; int r = n;
    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;
  }

}

Compilation message

events.cpp: In function 'int main()':
events.cpp:64:13: warning: variable 'S' set but not used [-Wunused-but-set-variable]
   64 |     Segment S; S.s = v[i].s; S.e = 1e9; S.idx = 1e9;
      |             ^

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23128 KB Output is correct
2 Correct 199 ms 39396 KB Output is correct
3 Correct 198 ms 39332 KB Output is correct
4 Correct 209 ms 39360 KB Output is correct
5 Correct 212 ms 39320 KB Output is correct
6 Correct 204 ms 39368 KB Output is correct
7 Correct 203 ms 39320 KB Output is correct
8 Correct 211 ms 39948 KB Output is correct
9 Correct 195 ms 39832 KB Output is correct
10 Correct 227 ms 39624 KB Output is correct
11 Correct 234 ms 40392 KB Output is correct
12 Correct 187 ms 39860 KB Output is correct

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 23132 KB Output is correct
2 Correct 14 ms 22940 KB Output is correct
3 Correct 14 ms 23256 KB Output is correct
4 Correct 16 ms 23132 KB Output is correct
5 Correct 14 ms 23132 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

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 23132 KB Output is correct
2 Correct 14 ms 22940 KB Output is correct
3 Correct 14 ms 23256 KB Output is correct
4 Correct 16 ms 23132 KB Output is correct
5 Correct 14 ms 23132 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

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 23132 KB Output is correct
2 Correct 14 ms 22940 KB Output is correct
3 Correct 14 ms 23256 KB Output is correct
4 Correct 16 ms 23132 KB Output is correct
5 Correct 14 ms 23132 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

# 결과 실행 시간 메모리 Grader output
1 Correct 199 ms 39324 KB Output is correct
2 Correct 210 ms 39232 KB Output is correct
3 Correct 225 ms 39652 KB Output is correct
4 Correct 195 ms 39876 KB Output is correct
5 Correct 255 ms 39608 KB Output is correct
6 Correct 223 ms 39468 KB Output is correct
7 Correct 219 ms 39368 KB Output is correct
8 Correct 233 ms 39876 KB Output is correct
9 Correct 63 ms 38568 KB Output is correct
10 Correct 199 ms 39108 KB Output is correct
11 Correct 216 ms 39064 KB Output is correct
12 Correct 199 ms 39036 KB Output is correct

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23128 KB Output is correct
2 Correct 199 ms 39396 KB Output is correct
3 Correct 198 ms 39332 KB Output is correct
4 Correct 209 ms 39360 KB Output is correct
5 Correct 212 ms 39320 KB Output is correct
6 Correct 204 ms 39368 KB Output is correct
7 Correct 203 ms 39320 KB Output is correct
8 Correct 211 ms 39948 KB Output is correct
9 Correct 195 ms 39832 KB Output is correct
10 Correct 227 ms 39624 KB Output is correct
11 Correct 234 ms 40392 KB Output is correct
12 Correct 187 ms 39860 KB Output is correct
13 Correct 13 ms 23132 KB Output is correct
14 Correct 14 ms 22940 KB Output is correct
15 Correct 14 ms 23256 KB Output is correct
16 Correct 16 ms 23132 KB Output is correct
17 Correct 14 ms 23132 KB Output is correct
18 Incorrect 14 ms 23132 KB Output isn't correct
19 Halted 0 ms 0 KB -