oj.uz

Submission #634768

# Submission time Handle Problem Language Result Execution time Memory
634768 2022-08-24T21:38:38 Z Ooops_sorry Parking (CEOI22_parking) C++14
20 / 100
 465 ms 123328 KB 
#define _GLIBCXX_DEBUG
#include<bits/stdc++.h>

using namespace std;

mt19937 rnd(51);

#define ll long long
#define pb push_back
#define ld long double

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    vector<vector<int>> a(m, vector<int>(2));
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < 2; j++) {
            cin >> a[i][j];
        }
    }
    int cnt = 0, cur = 0;
    vector<deque<pair<int,int>>> pos(n + 1);
    vector<vector<int>> val(m, vector<int>(2)), g(2 * n);
    vector<int> num(2 * n), ord;
    vector<bool> is_top(2 * n), used(2 * n);
    deque<int> cond, emp, non_emp;
    for (int i = 1; i <= n; i++) {
        cond.pb(i);
    }
    for (int i = 0; i < m; i++) {
        emp.pb(i);
        non_emp.pb(i);
    }
    for (int i = 0; i < m; i++) {
        while (a[i].size() > 0 && a[i].back() == 0) {
            a[i].pop_back();
        }
    }
    for (int i = 0; i < m; i++) {
        if (a[i].size() > 0) {
            num[cur] = a[i][0];
            val[i][0] = cur++;
            pos[a[i][0]].pb({i, 0});
        }
        if (a[i].size() > 1) {
            num[cur] = a[i][1];
            is_top[cur] = 1;
            val[i][1] = cur++;
            pos[a[i][1]].pb({i, 1});
        }
        if (a[i].size() > 1) {
            int x = val[i][0], y = val[i][1];
            g[x].pb(y);
            g[y].pb(x);
        }
    }
    for (int i = 1; i <= n; i++) {
        int x = val[pos[i][0].first][pos[i][0].second];
        int y = val[pos[i][1].first][pos[i][1].second];
        g[x].pb(y);
        g[y].pb(x);
    }
    for (int j = 1; j <= 2; j++) {
        for (int i = 0; i < 2 * n; i++) {
            if (used[i]) continue;
            if (g[i].size() <= j) {
                deque<int> q{i};
                used[i] = 1;
                while (q.size() > 0) {
                    int v = q.back();
                    q.pop_back();
                    for (auto to : g[v]) {
                        if (!used[to]) {
                            used[to] = 1;
                            q.pb(to);
                            if (is_top[v] && is_top[to]) {
                                ord.pb(num[v]);
                            }
                        }
                    }
                }
            }
        }
    }
    reverse(ord.begin(), ord.end());
    vector<pair<int,int>> ans;
    auto upd = [&](int i, int j) -> void {
        assert(i != j && a[i].size() > 0 && (a[j].size() == 0 || (a[j].size() == 1 && a[i].back() == a[j][0])));
        for (auto to : a[i]) {
            cond.pb(to);
        }
        for (auto to : a[j]) {
            cond.pb(to);
        }
        emp.pb(i);
        non_emp.pb(j);
        int val = a[i].back();
        if (pos[val][0].first == i) {
            pos[val].pop_front();
        } else {
            pos[val].pop_back();
        }
        pos[val].pb({j, a[j].size()});
        a[i].pop_back();
        a[j].pb(val);
        ans.pb({i, j});
    };
    while (1) {
        bool op = 0;
        while (cond.size() > 0) {
            int type = cond.back();
            cond.pop_back();
            if (pos[type][0].first == pos[type][1].first) continue;
            if (pos[type][0].second != 0) {
                swap(pos[type][0], pos[type][1]);
            }
            int i = pos[type][0].first, j = pos[type][1].first;
            if (pos[type][0].second == 0 && a[i].size() == 1 && a[j].size() == pos[type][1].second + 1) {
                upd(j, i);
                op = 1;
                break;
            }
        }
        if (op) continue;
        while (emp.size() > 0) {
            int i = emp.front();
            if (a[i].size() == 0) {
                break;
            }
            emp.pop_front();
        }
        if (ord.size() > 0) {
            if (emp.size() == 0) {
                cout << -1 << endl;
                return 0;
            }
            int type = ord.back();
            ord.pop_back();
            upd(pos[type][1].first, emp[0]);
            upd(pos[type][0].first, emp[0]);
            continue;
        }
        while (non_emp.size() > 0) {
            int i = non_emp.front();
            if (a[i].size() == 2 && (a[i][0] != a[i][1])) {
                break;
            }
            non_emp.pop_front();
        }
        if (non_emp.size() == 0) {
            break;
        }
        if (emp.size() == 0) {
            cout << -1 << endl;
            return 0;
        }
        upd(non_emp[0], emp[0]);
    }
    cout << ans.size() << endl;
    for (auto to : ans) {
        cout << to.first + 1 << ' ' << to.second + 1 << endl;
    }
    return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:71:29: warning: comparison of integer expressions of different signedness: 'std::__cxx1998::vector<int, std::allocator<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   71 |             if (g[i].size() <= j) {
      |                 ~~~~~~~~~~~~^~~~
Main.cpp:123:77: warning: comparison of integer expressions of different signedness: 'std::__cxx1998::vector<int, std::allocator<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  123 |             if (pos[type][0].second == 0 && a[i].size() == 1 && a[j].size() == pos[type][1].second + 1) {
      |                                                                 ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:26:9: warning: unused variable 'cnt' [-Wunused-variable]
   26 |     int cnt = 0, cur = 0;
      |         ^~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 308 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 382 ms 106228 KB Output is correct
2 Correct 465 ms 123328 KB Output is correct
3 Correct 297 ms 87544 KB Output is correct
4 Correct 255 ms 83016 KB Output is correct
5 Correct 455 ms 122432 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 980 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 980 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1236 KB Output is correct
2 Correct 2 ms 1236 KB Output is correct
3 Correct 3 ms 1108 KB Output is correct
4 Correct 2 ms 852 KB Output is correct
5 Correct 3 ms 1352 KB Output is correct
6 Correct 3 ms 1236 KB Output is correct
7 Correct 2 ms 1236 KB Output is correct
8 Correct 3 ms 1236 KB Output is correct
9 Correct 3 ms 1364 KB Output is correct
10 Correct 2 ms 1236 KB Output is correct
11 Correct 3 ms 1364 KB Output is correct
12 Correct 3 ms 1364 KB Output is correct
13 Correct 1 ms 1236 KB Output is correct
14 Correct 2 ms 1364 KB Output is correct
15 Correct 2 ms 1364 KB Output is correct
16 Incorrect 2 ms 1364 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 308 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 382 ms 106228 KB Output is correct
12 Correct 465 ms 123328 KB Output is correct
13 Correct 297 ms 87544 KB Output is correct
14 Correct 255 ms 83016 KB Output is correct
15 Correct 455 ms 122432 KB Output is correct
16 Incorrect 1 ms 980 KB Output isn't correct
17 Halted 0 ms 0 KB -