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Submission #699743

# Submission time Handle Problem Language Result Execution time Memory
699743 2023-02-17T21:44:09 Z Lobo Parking (CEOI22_parking) C++17
20 / 100
 122 ms 38652 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(); 
            if(done[i]) continue;
            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(); 
            if(done[i]) continue;
            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(); 
            if(done[i]) continue;
            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);
                }
                else if(in[x] == 1) {
                    sort(all(pos[x]));
                    int j = t[pos[x][0]]+t[pos[x][1]];
                    // cout << x << " " << t[pos[x][0]] << " " << t[pos[x][1]] << endl;
                    if(in[j] == 0) ot[out[j]].pb(j);
                }
            }
            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;
        }
    }

    // if(m-n != 0) {
    //     assert(ept.size() != 0);
    // }

    for(int i = 1; i <= n; i++) {
        if(done[i] == 0) {
            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 9 ms 19028 KB Output is correct
2 Correct 12 ms 19028 KB Output is correct
3 Correct 10 ms 19028 KB Output is correct
4 Correct 11 ms 19028 KB Output is correct
5 Correct 11 ms 19028 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 12 ms 19028 KB Output is correct
8 Correct 9 ms 19140 KB Output is correct
9 Correct 10 ms 19028 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 82 ms 32008 KB Output is correct
2 Correct 122 ms 33596 KB Output is correct
3 Correct 62 ms 29180 KB Output is correct
4 Correct 80 ms 29472 KB Output is correct
5 Correct 99 ms 33092 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 19144 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 19144 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 10 ms 19284 KB Output is correct
2 Correct 10 ms 19228 KB Output is correct
3 Correct 10 ms 19156 KB Output is correct
4 Runtime error 27 ms 38652 KB Execution killed with signal 11
5 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 19028 KB Output is correct
2 Correct 12 ms 19028 KB Output is correct
3 Correct 10 ms 19028 KB Output is correct
4 Correct 11 ms 19028 KB Output is correct
5 Correct 11 ms 19028 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 12 ms 19028 KB Output is correct
8 Correct 9 ms 19140 KB Output is correct
9 Correct 10 ms 19028 KB Output is correct
10 Correct 10 ms 19028 KB Output is correct
11 Correct 82 ms 32008 KB Output is correct
12 Correct 122 ms 33596 KB Output is correct
13 Correct 62 ms 29180 KB Output is correct
14 Correct 80 ms 29472 KB Output is correct
15 Correct 99 ms 33092 KB Output is correct
16 Incorrect 10 ms 19144 KB Output isn't correct
17 Halted 0 ms 0 KB -