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Submission #699715

# Submission time Handle Problem Language Result Execution time Memory
699715 2023-02-17T20:20:17 Z Lobo Parking (CEOI22_parking) C++17
20 / 100
 111 ms 33564 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) {
            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 10 ms 19028 KB Output is correct
2 Correct 11 ms 19028 KB Output is correct
3 Correct 10 ms 19112 KB Output is correct
4 Correct 10 ms 19028 KB Output is correct
5 Correct 10 ms 19124 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 10 ms 19028 KB Output is correct
8 Correct 12 ms 19088 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 90 ms 32032 KB Output is correct
2 Correct 110 ms 33564 KB Output is correct
3 Correct 70 ms 29180 KB Output is correct
4 Correct 60 ms 29544 KB Output is correct
5 Correct 111 ms 33096 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 10 ms 19284 KB Output is correct
2 Correct 11 ms 19284 KB Output is correct
3 Correct 13 ms 19264 KB Output is correct
4 Correct 11 ms 19128 KB Output is correct
5 Correct 10 ms 19156 KB Output is correct
6 Correct 11 ms 19156 KB Output is correct
7 Correct 10 ms 19156 KB Output is correct
8 Incorrect 14 ms 19228 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 10 ms 19028 KB Output is correct
2 Correct 11 ms 19028 KB Output is correct
3 Correct 10 ms 19112 KB Output is correct
4 Correct 10 ms 19028 KB Output is correct
5 Correct 10 ms 19124 KB Output is correct
6 Correct 10 ms 19028 KB Output is correct
7 Correct 10 ms 19028 KB Output is correct
8 Correct 12 ms 19088 KB Output is correct
9 Correct 10 ms 19028 KB Output is correct
10 Correct 10 ms 19028 KB Output is correct
11 Correct 90 ms 32032 KB Output is correct
12 Correct 110 ms 33564 KB Output is correct
13 Correct 70 ms 29180 KB Output is correct
14 Correct 60 ms 29544 KB Output is correct
15 Correct 111 ms 33096 KB Output is correct
16 Incorrect 10 ms 19156 KB Output isn't correct
17 Halted 0 ms 0 KB -