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Submission #699708

# Submission time Handle Problem Language Result Execution time Memory
699708 2023-02-17T20:11:14 Z Lobo Parking (CEOI22_parking) C++17
20 / 100
 107 ms 33580 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]);
                    }
                    else {
                        assert(false);
                    }

                    g[i].clear();
                    out[i] = 0;
                    break;
                }
            }
        }
        else {
            break;
        }
    }

    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 11 ms 19028 KB Output is correct
3 Correct 12 ms 19156 KB Output is correct
4 Correct 10 ms 19036 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 19076 KB Output is correct
8 Correct 12 ms 19156 KB Output is correct
9 Correct 9 ms 19028 KB Output is correct
10 Correct 9 ms 19132 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 87 ms 32004 KB Output is correct
2 Correct 107 ms 33580 KB Output is correct
3 Correct 66 ms 29180 KB Output is correct
4 Correct 57 ms 29524 KB Output is correct
5 Correct 106 ms 33076 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 19100 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 19100 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 19284 KB Output is correct
2 Correct 11 ms 19192 KB Output is correct
3 Correct 10 ms 19140 KB Output is correct
4 Correct 11 ms 19236 KB Output is correct
5 Correct 11 ms 19156 KB Output is correct
6 Correct 10 ms 19156 KB Output is correct
7 Correct 11 ms 19156 KB Output is correct
8 Incorrect 10 ms 19156 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 9 ms 19028 KB Output is correct
2 Correct 11 ms 19028 KB Output is correct
3 Correct 12 ms 19156 KB Output is correct
4 Correct 10 ms 19036 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 19076 KB Output is correct
8 Correct 12 ms 19156 KB Output is correct
9 Correct 9 ms 19028 KB Output is correct
10 Correct 9 ms 19132 KB Output is correct
11 Correct 87 ms 32004 KB Output is correct
12 Correct 107 ms 33580 KB Output is correct
13 Correct 66 ms 29180 KB Output is correct
14 Correct 57 ms 29524 KB Output is correct
15 Correct 106 ms 33076 KB Output is correct
16 Incorrect 10 ms 19100 KB Output isn't correct
17 Halted 0 ms 0 KB -