oj.uz

Submission #884285

# Submission time Handle Problem Language Result Execution time Memory
884285 2023-12-07T05:59:35 Z Kevin_Zhang_TW Parking (CEOI22_parking) C++17
50 / 100
 173 ms 44108 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].back() == i && stk[b].back() == 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 3 ms 14428 KB Output is correct
2 Correct 3 ms 14424 KB Output is correct
3 Correct 3 ms 14428 KB Output is correct
4 Correct 3 ms 14428 KB Output is correct
5 Correct 3 ms 14424 KB Output is correct
6 Correct 4 ms 14428 KB Output is correct
7 Correct 3 ms 14428 KB Output is correct
8 Correct 3 ms 14428 KB Output is correct
9 Correct 3 ms 14428 KB Output is correct
10 Correct 3 ms 14428 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 63 ms 44108 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 4 ms 14428 KB Output is correct
6 Correct 4 ms 14424 KB Output is correct
7 Correct 4 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 4 ms 14428 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 4 ms 14428 KB Output is correct
6 Correct 4 ms 14424 KB Output is correct
7 Correct 4 ms 14428 KB Output is correct
8 Correct 5 ms 14428 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 159 ms 31968 KB Output is correct
11 Correct 66 ms 26452 KB Output is correct
12 Correct 80 ms 26448 KB Output is correct
13 Correct 152 ms 30908 KB Output is correct
14 Correct 79 ms 26828 KB Output is correct
15 Correct 77 ms 26448 KB Output is correct
16 Correct 163 ms 32228 KB Output is correct
17 Correct 85 ms 26452 KB Output is correct
18 Correct 173 ms 31688 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Runtime error 16 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 3 ms 14428 KB Output is correct
2 Correct 3 ms 14424 KB Output is correct
3 Correct 3 ms 14428 KB Output is correct
4 Correct 3 ms 14428 KB Output is correct
5 Correct 3 ms 14424 KB Output is correct
6 Correct 4 ms 14428 KB Output is correct
7 Correct 3 ms 14428 KB Output is correct
8 Correct 3 ms 14428 KB Output is correct
9 Correct 3 ms 14428 KB Output is correct
10 Correct 3 ms 14428 KB Output is correct
11 Runtime error 63 ms 44108 KB Execution killed with signal 6
12 Halted 0 ms 0 KB -