oj.uz

Submission #699719

# Submission time Handle Problem Language Result Execution time Memory
699719 2023-02-17T20:22:13 Z Lobo Parking (CEOI22_parking) C++17
20 / 100
 127 ms 33636 KB 
#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 4e5+10;

int n, m, b[maxn], t[maxn], in[maxn], done[maxn], out[maxn];
vector<int> pos[maxn], ot[3], g[maxn];

void solve() {
    cin >> n >> m;
    vector<int> ept;
    int cntdone = 0;
    for(int i = 1; i <= m; i++) {
        cin >> b[i] >> t[i];
        
        if(b[i] == 0) {
            ept.pb(i);
            continue;
        }

        if(b[i] != 0) pos[b[i]].pb(i);
        if(t[i] != 0) pos[t[i]].pb(i+m);

        if(b[i] == t[i]) {
            done[b[i]] = 1; cntdone++;
        }
        else if(b[i] != 0 && t[i] != 0) {
            g[t[i]].pb(b[i]);
            out[t[i]]++;
            in[b[i]]++;
        }
    }

    for(int i = 1; i <= n; i++) {
        if(done[i] == 0 && in[i] == 0) {
            ot[out[i]].pb(i);
        }
    }

    vector<pair<int,int>> ans;
    while(true) {
        if(ot[0].size()) {
            int i = ot[0].back(); ot[0].pop_back(); done[i] = 1; cntdone++;
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p1,p2));
            b[p1] = 0;
            t[p2] = i;
            ept.pb(p1);
            pos[i][0] = p2+m;
        }
        else if(ot[1].size()) {
            int i = ot[1].back(); ot[1].pop_back(); done[i] = 1; cntdone++;
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p2,p1));
            t[p2-m] = 0;
            for(auto x : g[i]) {
                if(--in[x] == 0) {
                    ot[out[x]].pb(x);
                }
            }
            t[p1] = i;
            pos[i][1] = p1+m;
        }
        else if(ot[2].size() && ept.size()) {
            int i = ot[2].back(); ot[2].pop_back(); done[i] = 1; cntdone++;
            int e = ept.back(); ept.pop_back();
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p1,e));
            ans.pb(mp(p2,e));
            t[p1-m] = 0;
            t[p2-m] = 0;
            for(auto x : g[i]) {
                if(--in[x] == 0) {
                    ot[out[x]].pb(x);
                }
            }
            b[e] = i;
            t[e] = i;
            pos[i][0] = e;
            pos[i][1] = e+m;
        }
        else if(ept.size() && cntdone != n) {
            for(int j = 1; j <= m; j++) {
                if(b[j] != t[j]) {
                    int i = t[j];
                    int e = ept.back(); ept.pop_back();
                    sort(all(pos[i]));
                    ans.pb(mp(j,e));
                    t[j] = 0;
                    b[e] = i;
                    if(pos[i][0] == j+m) pos[i][0] = e;
                    else pos[i][1] = e;
                    if(--in[b[j]] == 0) {
                        ot[out[b[j]]].pb(b[j]);
                    }
                    assert((in[b[j]] == 0 && out[b[j]] == 1));
                    assert(g[i].size() == 1);
                    g[i].clear();
                    out[i] = 0;
                    break;
                }
            }
        }
        else {
            break;
        }
    }

    for(int i = 1; i <= n; i++) {
        if(done[i] == 0) {
            assert(cntdone != n);
            cout << -1 << endl;
            return;
        }
    }
    cout << ans.size() << endl;
    for(auto x : ans) {
        if(x.fr > m) x.fr-= m;
        if(x.sc > m) x.sc-= m;
        cout << x.fr << " " << x.sc << endl;
    }


}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 19028 KB Output is correct
2 Correct 9 ms 19028 KB Output is correct
3 Correct 9 ms 19048 KB Output is correct
4 Correct 10 ms 19028 KB Output is correct
5 Correct 10 ms 19028 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 10 ms 19028 KB Output is correct
8 Correct 10 ms 19028 KB Output is correct
9 Correct 10 ms 19080 KB Output is correct
10 Correct 10 ms 19028 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 90 ms 31972 KB Output is correct
2 Correct 102 ms 33636 KB Output is correct
3 Correct 65 ms 29144 KB Output is correct
4 Correct 60 ms 29556 KB Output is correct
5 Correct 127 ms 33152 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 19156 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 10 ms 19156 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 11 ms 19204 KB Output is correct
2 Correct 11 ms 19156 KB Output is correct
3 Correct 12 ms 19156 KB Output is correct
4 Correct 11 ms 19156 KB Output is correct
5 Correct 10 ms 19156 KB Output is correct
6 Correct 10 ms 19284 KB Output is correct
7 Correct 11 ms 19156 KB Output is correct
8 Incorrect 11 ms 19240 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 19028 KB Output is correct
2 Correct 9 ms 19028 KB Output is correct
3 Correct 9 ms 19048 KB Output is correct
4 Correct 10 ms 19028 KB Output is correct
5 Correct 10 ms 19028 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 10 ms 19028 KB Output is correct
8 Correct 10 ms 19028 KB Output is correct
9 Correct 10 ms 19080 KB Output is correct
10 Correct 10 ms 19028 KB Output is correct
11 Correct 90 ms 31972 KB Output is correct
12 Correct 102 ms 33636 KB Output is correct
13 Correct 65 ms 29144 KB Output is correct
14 Correct 60 ms 29556 KB Output is correct
15 Correct 127 ms 33152 KB Output is correct
16 Incorrect 10 ms 19156 KB Output isn't correct
17 Halted 0 ms 0 KB -