oj.uz

Submission #797299

# Submission time Handle Problem Language Result Execution time Memory
797299 2023-07-29T08:59:31 Z penguinman Thousands Islands (IOI22_islands) C++17
27.5 / 100
 42 ms 9172 KB 
#include "islands.h"

#include <bits/stdc++.h>
#include <variant>

using std::cin;
using std::cout;
using std::endl;
using std::vector;
using std::string;
using ll = int;
using vi = vector<ll>;
using vii = vector<vi>;
using pii = std::pair<ll,ll>;

#define rep(i,j,k) for(ll i=ll(j); i<ll(k); i++)
#define REP(i,j,k) for(ll i=ll(j); i<=ll(k); i++)
#define per(i,j,k) for(ll i=ll(j); i>=ll(k); i--)
#define all(a) a.begin(),a.end()
#define pb emplace_back
#define ln "\n"

struct directed_graph{
  ll N;
  vii edge, revedge;
  vi par;
  vii V;
  directed_graph(vii E){
    N = E.size();
    edge.resize(N);
    revedge.resize(N);
    par.resize(N);
    V.resize(N);
    rep(i,0,N){
      for(auto j: E[i]){
        edge[i].pb(j);
        revedge[j].pb(i);
      }
    }
  }
  vi ord;
  vector<bool> flag;
  void dfs1(ll now){
    flag[now] = true;
    for(auto next: edge[now]){
      if(flag[next]) continue;
      dfs1(next);
    }
    ord.pb(now);
  }
  void dfs2(ll p, ll now){
    flag[now] = true;
    par[now] = p;
    for(auto next: revedge[now]){
      if(flag[next]) continue;
      dfs2(p, next);
    }
  }
  void SCC(){
    flag.resize(N);
    rep(i,0,N){
      if(!flag[i]) dfs1(i);
    }
    reverse(all(ord));
    flag.assign(N,false);
    for(auto el: ord){
      if(!flag[el]){
        dfs2(el,el);
      }
    }
    rep(i,0,N) V[par[i]].pb(i);
  }
};

std::variant<bool, std::vector<int>> find_journey(int N, int M, std::vector<int> U, std::vector<int> V) {
  vii edge(N), index(N);
  rep(i,0,M){
    edge[U[i]].pb(V[i]);
    index[U[i]].pb(i);
  }
  directed_graph G(edge);
  G.SCC();
  ll good = -1;
  vi ans;
  {
    std::queue<ll> que;
    que.push(0);
    vi flag(N);
    vi rev(N,-1);
    vi idx(N);
    flag[0] = true;
    rev[0] = 0;
    while(!que.empty()){
      ll now = que.front(); que.pop();
      if(G.V[G.par[now]].size() >= 2 && edge[now].size() >= 2){
        good = now;
        while(now != 0){
          ans.pb(idx[now]);
          now = rev[now];
        }
        reverse(all(ans));
        break;
      }
      rep(i,0,edge[now].size()){
        ll next = edge[now][i];
        if(flag[next]) continue;
        flag[next] = true;
        rev[next] = now;
        idx[next] = index[now][i];
        que.push(next);
      }
    }
  }
  if(good != -1){
    std::set<ll> used;
    for(auto el: ans){
      used.insert(el);
      used.insert(el^1);
    }
    std::queue<ll> que;
    que.push(good);
    vi rev(N,-1);
    vi idx(N);
    rev[good] = good;
    while(!que.empty()){
      ll now = que.front(); que.pop();
      rep(i,0,edge[now].size()){
        ll next = edge[now][i];
        if(rev[next] != -1) continue;
        if(used.count(index[now][i])) continue;
        rev[next] = now;
        idx[next] = index[now][i];
        que.push(next);
      }
    }
    rep(i,0,N){
      if(rev[i] != -1){
        vi ans2;
        rep(j,0,edge[i].size()){
          if(used.count(index[i][j])) continue;
          ll next = edge[i][j];
          if(next == good){
            ans2.pb(index[i][j]);
            break;
          }
        }
        if(ans2.empty()) continue;
        ll now = i;
        while(now != good){
          ans2.pb(idx[now]);
          now = rev[now];
        }
        ll len = ans.size();
        reverse(all(ans2));
        for(auto el: ans2) ans.pb(el);
        for(auto el: ans2) ans.pb(el^1);
        reverse(all(ans2));
        for(auto el: ans2) ans.pb(el);
        for(auto el: ans2) ans.pb(el^1);
        per(i,len-1,0) ans.pb(ans[i]);
        return ans;
      }
    }
  }
  return false;
  
}

Subtask #1
1.75 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Partially correct 0 ms 212 KB Output is partially correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Partially correct 1 ms 212 KB Output is partially correct
7 Partially correct 30 ms 8692 KB Output is partially correct

Subtask #2
1.75 / 5.0

# Verdict Execution time Memory Grader output
1 Partially correct 1 ms 212 KB Output is partially correct
2 Correct 0 ms 212 KB Output is correct
3 Partially correct 0 ms 212 KB Output is partially correct
4 Partially correct 0 ms 212 KB Output is partially correct
5 Partially correct 0 ms 212 KB Output is partially correct
6 Partially correct 27 ms 6932 KB Output is partially correct

Subtask #3
0.0 / 21.0

# Verdict Execution time Memory Grader output
1 Partially correct 2 ms 596 KB Output is partially correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Partially correct 0 ms 212 KB Output is partially correct
5 Incorrect 1 ms 596 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 2 ms 468 KB Output is correct
3 Correct 26 ms 7484 KB Output is correct
4 Correct 28 ms 7992 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 3 ms 724 KB Output is correct
11 Correct 2 ms 596 KB Output is correct
12 Correct 1 ms 596 KB Output is correct
13 Correct 1 ms 596 KB Output is correct
14 Correct 2 ms 596 KB Output is correct
15 Correct 2 ms 724 KB Output is correct
16 Correct 1 ms 596 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 2 ms 596 KB Output is correct
19 Correct 1 ms 468 KB Output is correct
20 Correct 30 ms 8404 KB Output is correct
21 Correct 30 ms 7884 KB Output is correct
22 Correct 1 ms 596 KB Output is correct
23 Correct 1 ms 468 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 3 ms 596 KB Output is correct
27 Correct 33 ms 8476 KB Output is correct
28 Correct 34 ms 8452 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 32 ms 9164 KB Output is correct
31 Correct 0 ms 212 KB Output is correct
32 Correct 42 ms 8524 KB Output is correct
33 Correct 30 ms 8060 KB Output is correct
34 Correct 17 ms 4564 KB Output is correct
35 Correct 1 ms 468 KB Output is correct
36 Correct 27 ms 7068 KB Output is correct
37 Correct 30 ms 8704 KB Output is correct
38 Correct 1 ms 468 KB Output is correct
39 Correct 29 ms 7108 KB Output is correct
40 Correct 1 ms 596 KB Output is correct
41 Correct 34 ms 9172 KB Output is correct
42 Correct 35 ms 8572 KB Output is correct
43 Correct 1 ms 212 KB Output is correct
44 Correct 2 ms 596 KB Output is correct
45 Correct 1 ms 596 KB Output is correct
46 Correct 14 ms 4136 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Partially correct 0 ms 212 KB Output is partially correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Partially correct 1 ms 212 KB Output is partially correct
7 Partially correct 30 ms 8692 KB Output is partially correct
8 Partially correct 1 ms 212 KB Output is partially correct
9 Correct 0 ms 212 KB Output is correct
10 Partially correct 0 ms 212 KB Output is partially correct
11 Partially correct 0 ms 212 KB Output is partially correct
12 Partially correct 0 ms 212 KB Output is partially correct
13 Partially correct 27 ms 6932 KB Output is partially correct
14 Partially correct 2 ms 596 KB Output is partially correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Partially correct 0 ms 212 KB Output is partially correct
18 Incorrect 1 ms 596 KB Output isn't correct
19 Halted 0 ms 0 KB -