oj.uz

답안 #603310

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
603310 2022-07-24T00:10:23 Z DanerZein Event Hopping (BOI22_events) C++17
20 / 100
 1500 ms 38596 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<ii,int> iii;
typedef vector<ii> vii;
typedef vector<int> vi;
const int MAX_N=1e5+10;
const int MAX=1e9;
vector<vi> G;
vector<vii> que;
vii ev;
int dis[MAX_N];
int n;
bool isq[MAX_N];
void bfs(int u){
  for(int i=0;i<n;i++) dis[i]=MAX;
  dis[u]=0; isq[u]=1;
  queue<int> q; q.push(u);
  while(!q.empty()){
    int x=q.front(); q.pop();
    isq[x]=0;
    for(auto &v:G[x]){
      if(dis[v]>dis[x]+1){
	dis[v]=dis[x]+1;
	if(!isq[v]){
	  isq[v]=1;
	  q.push(v);
	}
      }
    }
  }
}
int in[MAX_N];
int pa[MAX_N][32];
int le[MAX_N];
void dfs(int u,int p){
  pa[u][0]=p;
  for(int i=1;i<=20;i++){
    pa[u][i]=pa[pa[u][i-1]][i-1];
  }
  for(auto &v:G[u]){
    if(v!=p) {
      le[v]=le[u]+1;
      dfs(v,u);
    }
  }
}
int father(int u,int v){
  int dif=le[u]-le[v];
  if(dif<0) return -1;
  for(int i=0;i<=20;i++){
    if(dif&(1<<i)) u=pa[u][i];
  }
  if(u!=v) return -1;
  return dif;
}
int con[MAX_N];
int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL); cout.tie(NULL);
  int q; cin>>n>>q;
  bool t2=0;
  if(n<=5000 ) t2=1;
  vii enp;
  for(int i=0;i<n;i++){
    int a,b; cin>>a>>b;
    ev.push_back(ii(a,b));
    enp.push_back(ii(b,i));
    con[i]=i;
  }
  G.resize(n+1);
  if(t2){
    for(int i=0;i<n;i++){
      for(int j=0;j<n;j++){
	if(ev[j].first<=ev[i].second && ev[i].second<=ev[j].second){
	  G[i].push_back(j);
	}
      }
    }
  }
  else{
    sort(enp.begin(),enp.end());
    for(int i=0;i<n-1;i++){
      if(enp[i].first==enp[i+1].first){
	con[enp[i].second]=enp[i+1].second;
	con[enp[i+1].second]=enp[i].second;
      }
    }
    for(int i=0;i<n;i++){
      auto it=lower_bound(enp.begin(),enp.end(),ii(ev[i].first,0));
      int l=it-enp.begin();
      it=upper_bound(enp.begin(),enp.end(),ii(ev[i].second+1,0));
      int r=it-enp.begin();
      for(int j=l;j<r;j++){
	if(i!=enp[j].second){
	  G[i].push_back(enp[j].second);
	  in[enp[j].second]=1;
	}
      }
    }
    for(int i=0;i<n;i++){
      if(!in[i] || con[i]!=i){
	dfs(i,i);
      }
    }
  }
  int iq=0;
  que.resize(n);
  while(q--){
    int s,e; cin>>s>>e;
    s--; e--;
    if(t2){
      que[s].push_back(ii(e,iq));
      iq++;
    }
    else{
      int ans=father(s,e);
      if(ans!=-1) cout<<ans<<endl;
      else{
	int ca=father(s,con[e])+1;
	if(ca!=0) cout<<ca<<endl;
	else
	  cout<<"impossible\n";
      }
    }
  }
  if(t2){
    vector<int> ans(iq);
    for(int i=0;i<n;i++){
      if(que[i].size()==0) continue;
      bfs(i);
      for(auto &v:que[i]){
	int s=i; int e=v.first;
	bfs(s);
	if(dis[e]>=MAX) ans[v.second]=-1;
	else ans[v.second]=dis[e];
      }
    }
    for(int i=0;i<ans.size();i++){
      if(ans[i]==-1) cout<<"impossible\n";
      else cout<<ans[i]<<endl;
    }
  }
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:140:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |     for(int i=0;i<ans.size();i++){
      |                 ~^~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 255 ms 30420 KB Output is correct
3 Correct 260 ms 30488 KB Output is correct
4 Correct 269 ms 30516 KB Output is correct
5 Correct 280 ms 29680 KB Output is correct
6 Correct 260 ms 28764 KB Output is correct
7 Correct 306 ms 28656 KB Output is correct
8 Correct 114 ms 22452 KB Output is correct
9 Correct 89 ms 21008 KB Output is correct
10 Correct 196 ms 27960 KB Output is correct
11 Correct 172 ms 25840 KB Output is correct
12 Correct 83 ms 24780 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 468 KB Output is correct
4 Correct 6 ms 468 KB Output is correct
5 Correct 7 ms 340 KB Output is correct
6 Correct 14 ms 1248 KB Output is correct
7 Correct 25 ms 2032 KB Output is correct
8 Correct 28 ms 3036 KB Output is correct
9 Correct 69 ms 4432 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 468 KB Output is correct
4 Correct 6 ms 468 KB Output is correct
5 Correct 7 ms 340 KB Output is correct
6 Correct 14 ms 1248 KB Output is correct
7 Correct 25 ms 2032 KB Output is correct
8 Correct 28 ms 3036 KB Output is correct
9 Correct 69 ms 4432 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 7 ms 340 KB Output is correct
13 Correct 6 ms 340 KB Output is correct
14 Correct 7 ms 388 KB Output is correct
15 Correct 12 ms 1240 KB Output is correct
16 Correct 25 ms 2004 KB Output is correct
17 Correct 32 ms 3088 KB Output is correct
18 Correct 72 ms 4428 KB Output is correct
19 Execution timed out 1561 ms 32236 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 468 KB Output is correct
4 Correct 6 ms 468 KB Output is correct
5 Correct 7 ms 340 KB Output is correct
6 Correct 14 ms 1248 KB Output is correct
7 Correct 25 ms 2032 KB Output is correct
8 Correct 28 ms 3036 KB Output is correct
9 Correct 69 ms 4432 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 8 ms 416 KB Output is correct
13 Correct 7 ms 464 KB Output is correct
14 Correct 9 ms 340 KB Output is correct
15 Correct 12 ms 1244 KB Output is correct
16 Correct 26 ms 2032 KB Output is correct
17 Correct 28 ms 3028 KB Output is correct
18 Correct 73 ms 4436 KB Output is correct
19 Correct 108 ms 29904 KB Output is correct
20 Execution timed out 1566 ms 21332 KB Time limit exceeded
21 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 240 ms 30400 KB Output is correct
2 Correct 262 ms 30380 KB Output is correct
3 Correct 269 ms 30404 KB Output is correct
4 Correct 87 ms 20860 KB Output is correct
5 Correct 188 ms 27572 KB Output is correct
6 Execution timed out 1554 ms 38596 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 255 ms 30420 KB Output is correct
3 Correct 260 ms 30488 KB Output is correct
4 Correct 269 ms 30516 KB Output is correct
5 Correct 280 ms 29680 KB Output is correct
6 Correct 260 ms 28764 KB Output is correct
7 Correct 306 ms 28656 KB Output is correct
8 Correct 114 ms 22452 KB Output is correct
9 Correct 89 ms 21008 KB Output is correct
10 Correct 196 ms 27960 KB Output is correct
11 Correct 172 ms 25840 KB Output is correct
12 Correct 83 ms 24780 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 7 ms 468 KB Output is correct
16 Correct 6 ms 468 KB Output is correct
17 Correct 7 ms 340 KB Output is correct
18 Correct 14 ms 1248 KB Output is correct
19 Correct 25 ms 2032 KB Output is correct
20 Correct 28 ms 3036 KB Output is correct
21 Correct 69 ms 4432 KB Output is correct
22 Correct 1 ms 212 KB Output is correct
23 Correct 0 ms 212 KB Output is correct
24 Correct 7 ms 340 KB Output is correct
25 Correct 6 ms 340 KB Output is correct
26 Correct 7 ms 388 KB Output is correct
27 Correct 12 ms 1240 KB Output is correct
28 Correct 25 ms 2004 KB Output is correct
29 Correct 32 ms 3088 KB Output is correct
30 Correct 72 ms 4428 KB Output is correct
31 Execution timed out 1561 ms 32236 KB Time limit exceeded
32 Halted 0 ms 0 KB -