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답안 #677462

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
677462 2023-01-03T11:51:22 Z stanislavpolyn Parking (CEOI22_parking) C++17
20 / 100
 144 ms 16528 KB 
#include <bits/stdc++.h>

#define fr(i, a, b) for (int i = (a); i <= (b); ++i)
#define rf(i, a, b) for (int i = (a); i >= (b); --i)
#define fe(x, y) for (auto& x : y)

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple

#define all(x) (x).begin(), (x).end()
#define pw(x) (1LL << (x))
#define sz(x) (int)(x).size()

using namespace std;

mt19937_64 rng(228);

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template <typename T>
bool umn(T& a, T b) {
    return a > b ? (a = b, 1) : 0;
}
template <typename T>
bool umx(T& a, T b) {
    return a < b ? (a = b, 1) : 0;
}

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T>
using ve = vector<T>;

const int N = 2e5 + 5;

int n, m;
int a[N][2];
ve<pii> opers;
ve<pii> pos[N];
set<int> emp;

void assertTL(bool f) {
    if (!f) {
        while (1);
    }
}

void doOper(int i, int j) {
    assertTL(i != j);
    assertTL(a[i][0]);

    int x = a[i][1] ? a[i][1] : a[i][0];

    int from = a[i][1] ? 1 : 0;
    assertTL(!a[j][1]);
    assertTL(a[j][0] == 0 || a[j][0] == x);

    int idx = -1;
    fr (cur, 0, 1) {
        if (pos[x][cur].fi == i && pos[x][cur].se == from) {
            idx = cur;
            break;
        }
    }
    assertTL(idx != -1);

    if (from == 0) {
        emp.insert(i);
    }

    if (a[j][0] == 0) {
        a[i][from] = 0;
        a[j][0] = x;
        pos[x][idx] = {j, 0};
        emp.erase(j);
    } else {
        assertTL(a[j][0]);
        a[i][from] = 0;
        a[j][1] = x;
        pos[x][idx] = {j, 1};
    }
    opers.pb({i, j});
}

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    ios::sync_with_stdio(0);
    cin.tie(0);
#endif

    cin >> n >> m;

    fr (i, 1, m) {
        cin >> a[i][0] >> a[i][1];

        if (a[i][0]) {
            pos[a[i][0]].pb({i, 0});
        }
        if (a[i][1]) {
            pos[a[i][1]].pb({i, 1});
        }
    }

    fr (i, 1, m) {
        if (!a[i][0]) {
            emp.insert(i);
        }
    }

    while (1) {
        bool found = 0;
        int cnt = 0;
        fr (i, 1, n) {
            if (pos[i][0].fi == pos[i][1].fi) {
                cnt++;
                continue;
            }

            int i1 = pos[i][0].fi;
            int j1 = pos[i][0].se;
            int i2 = pos[i][1].fi;
            int j2 = pos[i][1].se;

            if (j1 == 1 || !a[i1][1]) {
                if (j2 == 0 && !a[i2][1]) {
                    doOper(i1, i2);
                    found = 1;
                    continue;
                }
            }
            if (j2 == 1 || !a[i2][1]) {
                if (j1 == 0 && !a[i1][1]) {
                    doOper(i2, i1);
                    found = 1;
                }
            }
        }

        if (cnt == n) {
            fr (i, 1, m) {
                if (a[i][0]) {
                    assert(a[i][0] == a[i][1]);
                }
            }

//            assert(0);

            cout << sz(opers) << "\n";
            fe (x, opers) {
                cout << x.fi << " " << x.se << "\n";
            }
            return 0;
        }

        if (found) {
            continue;
        }

        fr (i, 1, n) {
            if (pos[i][0].fi == pos[i][1].fi) {
                continue;
            }

            int i1 = pos[i][0].fi;
            int j1 = pos[i][0].se;
            int i2 = pos[i][1].fi;
            int j2 = pos[i][1].se;

            if (j1 == 1 && j2 == 1) {
                if (sz(emp)) {
                    int to = *emp.begin();
                    doOper(i1, to);
                    doOper(i2, to);
                    found = 1;
                }
            }
        }

        if (found) {
            continue;
        }

//        cout << "YEP HERE\n";
        bool ok = 0;
        fr (i, 1, n) {
            if (pos[i][0].fi == pos[i][1].fi) {
               continue;
            }

            int i1 = pos[i][0].fi;
            int j1 = pos[i][0].se;
            int i2 = pos[i][1].fi;
            int j2 = pos[i][1].se;

            if (j1 != j2) {
                ok = 1;

                if (j1 == 0) {
                    if (sz(emp)) {
                        int to = *emp.begin();
                        doOper(i1, to);
                        doOper(i2, i1);
                        found = 1;
                        break;
                    }
                }
                if (j2 == 0) {
                    if (sz(emp)) {
                        int to = *emp.begin();
                        doOper(i2, to);
                        doOper(i1, i2);
                        found = 1;
                        break;
                    }
                }
            }
        }
        assert(ok);

        if (!found) {
            cout << "-1\n";
            return 0;
        }
    }

    return 0;
}

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 144 ms 16060 KB Output is correct
2 Correct 127 ms 16208 KB Output is correct
3 Correct 92 ms 15860 KB Output is correct
4 Correct 93 ms 15924 KB Output is correct
5 Correct 123 ms 16528 KB Output is correct

Subtask #3
0.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 3 ms 4948 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 3 ms 4948 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5060 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 5 ms 5076 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 4 ms 5076 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Incorrect 4 ms 4948 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 144 ms 16060 KB Output is correct
12 Correct 127 ms 16208 KB Output is correct
13 Correct 92 ms 15860 KB Output is correct
14 Correct 93 ms 15924 KB Output is correct
15 Correct 123 ms 16528 KB Output is correct
16 Incorrect 3 ms 4948 KB Output isn't correct
17 Halted 0 ms 0 KB -