oj.uz

답안 #884272

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
884272 2023-12-07T05:45:33 Z Kevin_Zhang_TW Parking (CEOI22_parking) C++17
40 / 100
 196 ms 42444 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, v);
      no_more_care(o);
    }
  };

  for (int i = 0;i < m;++i) if (stk[i].size() == 1) {
    no_more_care(i);
  }
  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
0.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 13 ms 29032 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #2
0.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 49 ms 42444 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 14428 KB Output is correct
2 Correct 3 ms 14428 KB Output is correct
3 Correct 4 ms 14428 KB Output is correct
4 Correct 4 ms 14428 KB Output is correct
5 Correct 3 ms 14424 KB Output is correct
6 Correct 4 ms 14424 KB Output is correct
7 Correct 4 ms 14424 KB Output is correct
8 Correct 4 ms 14424 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 14428 KB Output is correct
2 Correct 3 ms 14428 KB Output is correct
3 Correct 4 ms 14428 KB Output is correct
4 Correct 4 ms 14428 KB Output is correct
5 Correct 3 ms 14424 KB Output is correct
6 Correct 4 ms 14424 KB Output is correct
7 Correct 4 ms 14424 KB Output is correct
8 Correct 4 ms 14424 KB Output is correct
9 Correct 4 ms 14428 KB Output is correct
10 Correct 154 ms 32072 KB Output is correct
11 Correct 66 ms 26448 KB Output is correct
12 Correct 99 ms 26564 KB Output is correct
13 Correct 159 ms 30768 KB Output is correct
14 Correct 86 ms 26964 KB Output is correct
15 Correct 111 ms 26368 KB Output is correct
16 Correct 196 ms 32204 KB Output is correct
17 Correct 83 ms 26448 KB Output is correct
18 Correct 156 ms 31560 KB Output is correct

Subtask #5
0.0 / 25.0

# 결과 실행 시간 메모리 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

# 결과 실행 시간 메모리 Grader output
1 Runtime error 13 ms 29032 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -