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답안 #677479

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
677479 2023-01-03T12:29:01 Z stanislavpolyn Parking (CEOI22_parking) C++17
20 / 100
 141 ms 16488 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);
    }
}

bool TL() {
    return (double)clock() / CLOCKS_PER_SEC > 1.9;
}

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});

//    fr (i, 1, m) {
//        if (!a[i][0]) assertTL(emp.count(i));
//        else assertTL(!emp.count(i));
//
//        if (a[i][0]) assertTL(pos[a[i][0]][0] == mp(i, 0) || pos[a[i][0]][1] == mp(i, 0));
//        if (a[i][1]) assertTL(pos[a[i][1]][0] == mp(i, 1) || pos[a[i][1]][1] == mp(i, 1));
//        if (a[i][1]) {
//            assertTL(a[i][0]);
//        }
//    }
}

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;

    assert(n <= int(2e5));
    assert(n >= 1);
    assert(m <= int(2e5));

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

        assert(a[i][0] >= 0 && a[i][0] <= n);
        assert(a[i][1] >= 0 && a[i][1] <= n);

        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, n) {
        assert(sz(pos[i]) == 2);
    }

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

    while (1) {
        bool found = 0;
        int cnt = 0;
        int was = sz(emp);
        
        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;
                }
            }
        }

        assert(sz(emp) >= was);
        
        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;
        }

        if (!sz(emp)) {
            cout << "-1\n";
           
           bool have = 0;
            fr (i, 1, m) {
                fr (j, 1, m) {
                    if (i == j) continue;
                    if (!a[i][0]) continue;
                    if (a[j][1]) continue;

                    int x = a[i][1] ? a[i][1] : a[i][0];
                    if (!a[j][0] || a[j][0] == x) {
                        have = 1;
                    }
                }
            }

            assert(!have);
            
            return 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 == 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";
        fr (i, 1, n) {
            if (pos[i][0].fi == pos[i][1].fi) {
               continue;
            }

            if (sz(emp)) {
                assert(pos[i][0].se != pos[i][1].se);
            }
        }

        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) {
            bool have = 0;
            fr (i, 1, m) {
                fr (j, 1, m) {
                    if (i == j) continue;
                    if (!a[i][0]) continue;
                    if (a[j][1]) continue;

                    int x = a[i][1] ? a[i][1] : a[i][0];
                    if (!a[j][0] || a[j][0] == x) {
                        have = 1;
                    }
                }
            }

            assert(!have);

            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 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 5000 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 128 ms 16064 KB Output is correct
2 Correct 111 ms 16144 KB Output is correct
3 Correct 97 ms 15924 KB Output is correct
4 Correct 88 ms 15980 KB Output is correct
5 Correct 141 ms 16488 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 3 ms 5076 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 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 3 ms 5076 KB Output is correct
7 Correct 4 ms 5072 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 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 5000 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 128 ms 16064 KB Output is correct
12 Correct 111 ms 16144 KB Output is correct
13 Correct 97 ms 15924 KB Output is correct
14 Correct 88 ms 15980 KB Output is correct
15 Correct 141 ms 16488 KB Output is correct
16 Incorrect 3 ms 4948 KB Output isn't correct
17 Halted 0 ms 0 KB -