oj.uz

Submission #884284

# Submission time Handle Problem Language Result Execution time Memory
884284 2023-12-07T05:57:51 Z Kevin_Zhang_TW Parking (CEOI22_parking) C++17
50 / 100
 198 ms 44360 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l)==r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
// My bug list :
// integer overflow
// 0based, 1based forgotten
// index out of bound
// n, m, i, j typo
// some cases are missing

const int MAX_N = 300010;

int n, m;
vector<int> stk[MAX_N], emp;
vector<int> at[MAX_N];
void fail() {
  cout << -1 << '\n';
  exit(0);
}
int32_t main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  cin >> n >> m;
  for (int i = 0;i < m;++i) {
    int b, t;
    cin >> b >> t;
    for (int j : {b, t}) if (j) {
      stk[i].pb(j);
      at[j].pb(i);
    }
    if (b == 0) emp.pb(i);
  }

  vector<pair<int,int>> res;
  // all full or empty
//
//  vector<pair<int,int>> ud;
  auto hp = [&]() {
    DE("stk");
    for (int i = 0;i < m;++i)
      debug(AI(stk[i]));
  };
  auto atob = [&](int a, int b) {
    int v = stk[a].back(); stk[a].pop_back();
    stk[b].pb(v);
    *find(AI(at[v]), a) = b;
    res.pb(a, b);
  };
  auto other = [&](int x, int p) {
    return at[x][0] + at[x][1] - p;
  };
  auto shift = [&](int p) {
    assert(stk[p].size() == 1);
    int v = stk[p][0], o = other(v, p);
    while (stk[o].size() == 2 && stk[o][1] == v) {
      atob(o, p);
      p = o;
      v = stk[p][0];
      o = other(v, p);
    }
    return p;
  };
  auto eqtop = [&](int p) {
    int v = stk[p][1], o = other(v, p);
    while (stk[o][0] == v) {
      p = o;
      v = stk[p][1], o = other(v, p);
    }
    return p;
  };
  function<void(int)> take_care = [&](int p) {
    if (emp.empty()) fail();
    if (stk[p].empty()) {
      emp.pb(p);
      return;
    }
    assert(stk[p].size() == 1);
    int v = stk[p][0];
    int e = emp.back(), o = other(v, p);
    if (stk[o].size() == 1 || stk[o][1] == v) {
      atob(o, p);
      take_care(o);
      return;
    }
    int g = eqtop(o);
    atob(g, e);
    shift(g);
    atob(o, p);
    emp.back() = o;
    take_care(e);
  };

  function<void(int)> no_more_care = [&](int p) {
    if (stk[p].empty()) {
      emp.pb(p);
      return;
    }
    assert(stk[p].size() == 1);
    int v = stk[p][0];
    int o = other(v, p);
    if (stk[o].back() == v) {
      atob(o, p);
      no_more_care(o);
    }
  };

  for (int i = 0;i < m;++i) if (stk[i].size() == 1) {
    no_more_care(i);
  }
  //hp();
//  for (int i = 0;i < m;++i) if (stk[i].size() == 1)
//    take_care(i);
//    int x = stk[i][0];
//    if (stk[other(x, i)].back() == x)
//      take_
  for (int i = 1;i <= n;++i) {
    int a = at[i][0], b = at[i][1];
    if (a == b) continue;
    if (stk[a][1] == i && stk[b][1] == i) {
      if (emp.empty()) fail();
      int e = emp.back(); emp.pop_back();
      atob(a, e);
      atob(b, e);
      a = shift(a), b = shift(b);
      if (stk[a][0] == stk[b][0]) {
        atob(a, b);
        emp.pb(a);
      } else {
        take_care(a);
      }
    }
  }

  for (int i = 1;i <= n;++i) {
    int a = at[i][0], b = at[i][1];
    if (a == b) continue;
    if (emp.empty()) fail();
    if (stk[a][0] != i) swap(a, b);
    // stk[a][0] = i
    int e = emp.back();
    atob(a, e);
    int g = shift(a);
    atob(e, g);
    // must be one up and one down
  }
  for (int i = 1;i <= n;++i) assert(at[i][0] == at[i][1]);

  cout << res.size() << '\n';
  for (auto [a, b] : res) {
    ++a, ++b;
    cout << a << ' ' << b << '\n';
  }
}

Compilation message

Main.cpp: In lambda function:
Main.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
Main.cpp:51:5: note: in expansion of macro 'DE'
   51 |     DE("stk");
      |     ^~
Main.cpp:15:20: warning: statement has no effect [-Wunused-value]
   15 | #define debug(...) 0
      |                    ^
Main.cpp:53:7: note: in expansion of macro 'debug'
   53 |       debug(AI(stk[i]));
      |       ^~~~~
Main.cpp: In function 'int32_t main()':
Main.cpp:50:8: warning: variable 'hp' set but not used [-Wunused-but-set-variable]
   50 |   auto hp = [&]() {
      |        ^~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 14424 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 3 ms 14428 KB Output is correct
4 Correct 3 ms 14428 KB Output is correct
5 Correct 4 ms 14548 KB Output is correct
6 Correct 3 ms 14428 KB Output is correct
7 Correct 3 ms 14428 KB Output is correct
8 Correct 4 ms 14424 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 4 ms 14424 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 65 ms 44360 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 14428 KB Output is correct
2 Correct 4 ms 14428 KB Output is correct
3 Correct 4 ms 14428 KB Output is correct
4 Correct 4 ms 14424 KB Output is correct
5 Correct 3 ms 14428 KB Output is correct
6 Correct 3 ms 14424 KB Output is correct
7 Correct 4 ms 14600 KB Output is correct
8 Correct 4 ms 14428 KB Output is correct
9 Correct 4 ms 14680 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 14428 KB Output is correct
2 Correct 4 ms 14428 KB Output is correct
3 Correct 4 ms 14428 KB Output is correct
4 Correct 4 ms 14424 KB Output is correct
5 Correct 3 ms 14428 KB Output is correct
6 Correct 3 ms 14424 KB Output is correct
7 Correct 4 ms 14600 KB Output is correct
8 Correct 4 ms 14428 KB Output is correct
9 Correct 4 ms 14680 KB Output is correct
10 Correct 184 ms 31940 KB Output is correct
11 Correct 68 ms 26452 KB Output is correct
12 Correct 80 ms 26448 KB Output is correct
13 Correct 198 ms 31072 KB Output is correct
14 Correct 94 ms 26916 KB Output is correct
15 Correct 76 ms 26560 KB Output is correct
16 Correct 184 ms 32200 KB Output is correct
17 Correct 76 ms 26448 KB Output is correct
18 Correct 175 ms 31652 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Runtime error 13 ms 29276 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 14424 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 3 ms 14428 KB Output is correct
4 Correct 3 ms 14428 KB Output is correct
5 Correct 4 ms 14548 KB Output is correct
6 Correct 3 ms 14428 KB Output is correct
7 Correct 3 ms 14428 KB Output is correct
8 Correct 4 ms 14424 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 4 ms 14424 KB Output is correct
11 Runtime error 65 ms 44360 KB Execution killed with signal 6
12 Halted 0 ms 0 KB -