oj.uz

Submission #864741

# Submission time Handle Problem Language Result Execution time Memory
864741 2023-10-23T14:08:42 Z mychecksedad Parking (CEOI22_parking) C++17
10 / 100
 62 ms 18144 KB 
/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


int n, m, A[N], B[N], AA = MOD;
vector<pair<int, int>> ans;
vector<vector<int>> v;
vector<int> E;
  
void move(int i, int j){
  if(i==j) return;
  int x = v[i].back();
  ans.pb({i, j});
  v[j].pb(x);
  v[i].pop_back();
  if(v[i].empty()) E.pb(i);
}

void solve(){
  cin >> n >> m;
  v.resize(m);
  for(int i = 0; i < m; ++i){
    cin >> B[i] >> A[i];
    if(B[i] > 0) v[i].pb(B[i]);
    if(A[i] > 0) v[i].pb(A[i]);
  }
  bool ok = 1;
  for(int i = 0; i < m; ++i) if(v[i].empty()) E.pb(i);
  while(ok){
    ok = 0;
    vector<int> one(n+1, -1), up(n+1, -1);
    for(int i = 0; i < m; ++i){
      if(v[i].empty()) continue;
      else if(v[i].size() == 1){
        if(one[v[i][0]] != -1){
          ok = 1;
          move(i, one[v[i][0]]);
          continue;
        }
        if(up[v[i][0]] != -1){
          ok = 1;
          move(up[v[i][0]], i);
          continue;
        }
        one[v[i][0]] = i;
      }else{
        if(v[i][0] == v[i][1]) continue;
        if(up[v[i][1]] != -1 && (v[up[v[i][1]]][0] == v[i][0] || E.size() > 1)){
          if(!E.empty()){
            int pos = E.back();
            E.pop_back();
            move(up[v[i][1]], pos);
            move(i, pos);
            move(up[v[i][1]], i);
            ok = 1;
          }
          continue;   
        }
        if(one[v[i][1]] != -1){
          ok = 1;
          move(i, one[v[i][1]]);
          continue;
        }
        up[v[i][1]] = i;
      }
    }
    if(ok) continue;
    if(E.empty()) break;
    for(int i = 0; i < m; ++i){
      if(v[i].size() == 2){
        if(v[i][0] == v[i][1]) continue;
        if(up[v[i][1]] == i){
          move(i, E.back());
          E.pop_back();
          ok = 1;
          break;
        }
        up[v[i][1]] = i;
      }
    }
    if(ok) continue;
    for(int i = 0; i < m; ++i){
      if(v[i].size() == 2){
        if(v[i][0] == v[i][1]) continue;
        move(i, E.back());
        E.pop_back();
        ok = 1;
        break;
      }
    }
  }
  ok = 1;
  for(int i = 0; i < m; ++i){
    if(v[i].empty()) continue;
    if(v[i].size() == 1) ok = 0;
    else{
      ok &= (v[i][0] == v[i][1]);
    }
  }

  if(!ok){
    cout << -1;
    return;
  }

  cout << ans.size() << '\n';
  for(auto x: ans) cout << x.first + 1 << ' ' << x.second + 1 << '\n';
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:121:15: warning: unused variable 'aa' [-Wunused-variable]
  121 |   int tt = 1, aa;
      |               ^~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2392 KB Output is correct
4 Correct 1 ms 2392 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2804 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2392 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 62 ms 18144 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 2648 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 2648 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 2648 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2392 KB Output is correct
4 Correct 1 ms 2392 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2804 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2392 KB Output is correct
11 Incorrect 62 ms 18144 KB Output isn't correct
12 Halted 0 ms 0 KB -