oj.uz

Submission #781630

# Submission time Handle Problem Language Result Execution time Memory
781630 2023-07-13T08:53:09 Z devariaota Naboj (COCI22_naboj) C++17
110 / 110
 441 ms 39668 KB 
#include <bits/stdc++.h>
using namespace std;

# define int long long
# define fir first
# define sec second
# define pb push_back

const int cnst = 2e5+5;
bool mutipletestcase = 0;
//bool debug = false;

int x[cnst], y[cnst];
int dis[cnst];
vector<int> vec[cnst], vec2[cnst];


// void dfs(int x) {
//     for(auto v: vec[x]) {
//         if(dis[v] != 0) continue;
//         dis[v] = dis[x]+1;
//         dfs(v);
//     }
// }

void solve() {
    int n, m; cin >> n >> m;

    for(int i = 1; i<=m; i++) {
        int a, b; cin >> a >> b;
        vec[a].pb(b);
        vec2[b].pb(a);
        x[a]++; y[b]++;
    }

    // bool yes = 0;
    // for(int i = 1; i<=n; i++) if(!y[i]) yes = 1; 

    // if(!yes) {cout << "-1" << endl; return;}

    queue<int> q;
    int done = 0;

    for(int i = 1; i<=n; i++) {
        if(!x[i]) q.push(i), done++;
    }

    vector<pair<int, int>> ans;

    while(!q.empty()) {
        int a = q.front(); q.pop();

        for(auto v: vec2[a]) {
            x[v]--;
            if(!x[v]) {
                q.push(v);
                ans.pb({v, 1});
                done++;
            }
        }

        // cerr << a << " " << done << endl;
        // if(done != n) ans.pb({a, 0});
        if(done == n) break;
    }

    if(done == n) {
        cout << ans.size() << endl;
        for(auto v: ans) cout << v.fir << " " << v.sec << endl;
    }
    else cout << -1 << endl;

}

signed main() {
    ios_base::sync_with_stdio(false);
    int t = 1;
    if(mutipletestcase) cin >> t; 
    while(t--) solve();
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9684 KB Output is correct
2 Correct 5 ms 9684 KB Output is correct
3 Correct 5 ms 9684 KB Output is correct
4 Correct 4 ms 9684 KB Output is correct
5 Correct 5 ms 9684 KB Output is correct
6 Correct 5 ms 9684 KB Output is correct
7 Correct 5 ms 9684 KB Output is correct
8 Correct 4 ms 9684 KB Output is correct
9 Correct 5 ms 9684 KB Output is correct
10 Correct 5 ms 9684 KB Output is correct
11 Correct 5 ms 9728 KB Output is correct
12 Correct 5 ms 9720 KB Output is correct
13 Correct 5 ms 9684 KB Output is correct
14 Correct 5 ms 9684 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 243 ms 26556 KB Output is correct
2 Correct 279 ms 29004 KB Output is correct
3 Correct 122 ms 19784 KB Output is correct
4 Correct 257 ms 29052 KB Output is correct
5 Correct 273 ms 29016 KB Output is correct
6 Correct 248 ms 28984 KB Output is correct
7 Correct 275 ms 28960 KB Output is correct
8 Correct 183 ms 24012 KB Output is correct
9 Correct 247 ms 29072 KB Output is correct
10 Correct 295 ms 28988 KB Output is correct

Subtask #3
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9684 KB Output is correct
2 Correct 5 ms 9684 KB Output is correct
3 Correct 5 ms 9684 KB Output is correct
4 Correct 4 ms 9684 KB Output is correct
5 Correct 5 ms 9684 KB Output is correct
6 Correct 5 ms 9684 KB Output is correct
7 Correct 5 ms 9684 KB Output is correct
8 Correct 4 ms 9684 KB Output is correct
9 Correct 5 ms 9684 KB Output is correct
10 Correct 5 ms 9684 KB Output is correct
11 Correct 5 ms 9728 KB Output is correct
12 Correct 5 ms 9720 KB Output is correct
13 Correct 5 ms 9684 KB Output is correct
14 Correct 5 ms 9684 KB Output is correct
15 Correct 243 ms 26556 KB Output is correct
16 Correct 279 ms 29004 KB Output is correct
17 Correct 122 ms 19784 KB Output is correct
18 Correct 257 ms 29052 KB Output is correct
19 Correct 273 ms 29016 KB Output is correct
20 Correct 248 ms 28984 KB Output is correct
21 Correct 275 ms 28960 KB Output is correct
22 Correct 183 ms 24012 KB Output is correct
23 Correct 247 ms 29072 KB Output is correct
24 Correct 295 ms 28988 KB Output is correct
25 Correct 165 ms 30016 KB Output is correct
26 Correct 175 ms 29428 KB Output is correct
27 Correct 208 ms 31568 KB Output is correct
28 Correct 271 ms 35248 KB Output is correct
29 Correct 143 ms 28608 KB Output is correct
30 Correct 243 ms 34792 KB Output is correct
31 Correct 37 ms 13496 KB Output is correct
32 Correct 237 ms 29544 KB Output is correct
33 Correct 395 ms 38168 KB Output is correct
34 Correct 255 ms 30260 KB Output is correct
35 Correct 401 ms 38444 KB Output is correct
36 Correct 232 ms 29320 KB Output is correct
37 Correct 364 ms 36544 KB Output is correct
38 Correct 339 ms 34328 KB Output is correct
39 Correct 387 ms 37992 KB Output is correct
40 Correct 357 ms 35600 KB Output is correct
41 Correct 345 ms 35336 KB Output is correct
42 Correct 414 ms 39368 KB Output is correct
43 Correct 293 ms 31048 KB Output is correct
44 Correct 441 ms 39668 KB Output is correct
45 Correct 283 ms 30188 KB Output is correct
46 Correct 386 ms 35544 KB Output is correct