oj.uz

Submission #677199

# Submission time Handle Problem Language Result Execution time Memory
677199 2023-01-02T14:30:30 Z dooompy Network (BOI15_net) C++17
100 / 100
 416 ms 48164 KB 
#include "bits/stdc++.h"
 
using namespace std;
 
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T a, U ...b) {
    cout << a << ' ', abc(b...);
}
template <typename T> void printv(T l, T r) {
    while (l != r) cout << *l << " \n"[++l == r];
}
template <typename A, typename B> istream& operator >> (istream& o, pair<A, B> &a) {
    return o >> a.first >> a.second;
}
template <typename A, typename B> ostream& operator << (ostream& o, pair<A, B> a) {
    return o << '(' << a.first << ", " << a.second << ')';
}
template <typename T> ostream& operator << (ostream& o, vector<T> a) {
    bool is = false;
    for (T i : a) {o << (is ? ' ' : '{'), is = true, o << i;}
    return o << '}';
}
 
#ifdef local
#define test(args...) abc("[" + string(#args) + "]", args)
#else
#define test(args...) void(0)
#endif
 
using ll = long long;
 
vector<int> adj[500005];
bool seen[500005];
vector<int> order;
 
void dfs(int node) {
    seen[node] = true;
    bool leaf = true;
    for (auto nxt : adj[node]) {
        if (seen[nxt]) continue;
        dfs(nxt);
        leaf = false;
    }
    if (leaf) order.push_back(node);
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
//    freopen("", "r", stdin);
//    freopen("", "w", stdout);
    int n; cin >> n;
    for (int i = 0; i < n-1; i++) {
        int a, b; cin >>a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
 
    for (int i = 1; i <= n; i++) {
        if (adj[i].size() >= 2) {
            dfs(i);
            break;
        }
    }
 
    int s = order.size();
 
    cout << ceil(s / 2.0) << endl;
 
    for (int i = 0; i < (s + 1) /2; i++) {
        cout << order[i] << " " << order[min(i + s/2, s-1)] << "\n";
    }
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 7 ms 12068 KB Output is correct
3 Correct 6 ms 12068 KB Output is correct
4 Correct 6 ms 12064 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 12068 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 12044 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 7 ms 12132 KB Output is correct
17 Correct 8 ms 12064 KB Output is correct
18 Correct 6 ms 12068 KB Output is correct
19 Correct 6 ms 11988 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 7 ms 12068 KB Output is correct
3 Correct 6 ms 12068 KB Output is correct
4 Correct 6 ms 12064 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 12068 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 12044 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 7 ms 12132 KB Output is correct
17 Correct 8 ms 12064 KB Output is correct
18 Correct 6 ms 12068 KB Output is correct
19 Correct 6 ms 11988 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct
21 Correct 7 ms 11988 KB Output is correct
22 Correct 7 ms 12116 KB Output is correct
23 Correct 7 ms 12072 KB Output is correct
24 Correct 7 ms 12116 KB Output is correct
25 Correct 7 ms 12116 KB Output is correct
26 Correct 7 ms 12044 KB Output is correct
27 Correct 8 ms 12076 KB Output is correct
28 Correct 7 ms 12080 KB Output is correct
29 Correct 7 ms 12080 KB Output is correct
30 Correct 6 ms 11988 KB Output is correct
31 Correct 8 ms 12116 KB Output is correct
32 Correct 7 ms 12016 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 6 ms 11988 KB Output is correct
35 Correct 6 ms 12068 KB Output is correct
36 Correct 6 ms 11988 KB Output is correct
37 Correct 8 ms 12076 KB Output is correct
38 Correct 8 ms 12120 KB Output is correct
39 Correct 7 ms 11988 KB Output is correct
40 Correct 7 ms 11980 KB Output is correct
41 Correct 7 ms 11988 KB Output is correct
42 Correct 7 ms 12012 KB Output is correct
43 Correct 6 ms 12068 KB Output is correct
44 Correct 6 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 7 ms 11988 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 12072 KB Output is correct
49 Correct 7 ms 12116 KB Output is correct
50 Correct 8 ms 11988 KB Output is correct
51 Correct 7 ms 11988 KB Output is correct
52 Correct 8 ms 12072 KB Output is correct
53 Correct 7 ms 12116 KB Output is correct
54 Correct 7 ms 11976 KB Output is correct
55 Correct 7 ms 11988 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 6 ms 12068 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 7 ms 12068 KB Output is correct
3 Correct 6 ms 12068 KB Output is correct
4 Correct 6 ms 12064 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 12068 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 12044 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 7 ms 12132 KB Output is correct
17 Correct 8 ms 12064 KB Output is correct
18 Correct 6 ms 12068 KB Output is correct
19 Correct 6 ms 11988 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct
21 Correct 7 ms 11988 KB Output is correct
22 Correct 7 ms 12116 KB Output is correct
23 Correct 7 ms 12072 KB Output is correct
24 Correct 7 ms 12116 KB Output is correct
25 Correct 7 ms 12116 KB Output is correct
26 Correct 7 ms 12044 KB Output is correct
27 Correct 8 ms 12076 KB Output is correct
28 Correct 7 ms 12080 KB Output is correct
29 Correct 7 ms 12080 KB Output is correct
30 Correct 6 ms 11988 KB Output is correct
31 Correct 8 ms 12116 KB Output is correct
32 Correct 7 ms 12016 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 6 ms 11988 KB Output is correct
35 Correct 6 ms 12068 KB Output is correct
36 Correct 6 ms 11988 KB Output is correct
37 Correct 8 ms 12076 KB Output is correct
38 Correct 8 ms 12120 KB Output is correct
39 Correct 7 ms 11988 KB Output is correct
40 Correct 7 ms 11980 KB Output is correct
41 Correct 7 ms 11988 KB Output is correct
42 Correct 7 ms 12012 KB Output is correct
43 Correct 6 ms 12068 KB Output is correct
44 Correct 6 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 7 ms 11988 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 12072 KB Output is correct
49 Correct 7 ms 12116 KB Output is correct
50 Correct 8 ms 11988 KB Output is correct
51 Correct 7 ms 11988 KB Output is correct
52 Correct 8 ms 12072 KB Output is correct
53 Correct 7 ms 12116 KB Output is correct
54 Correct 7 ms 11976 KB Output is correct
55 Correct 7 ms 11988 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 6 ms 12068 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct
59 Correct 280 ms 36424 KB Output is correct
60 Correct 332 ms 39248 KB Output is correct
61 Correct 7 ms 11988 KB Output is correct
62 Correct 7 ms 11988 KB Output is correct
63 Correct 239 ms 34004 KB Output is correct
64 Correct 8 ms 12500 KB Output is correct
65 Correct 14 ms 13968 KB Output is correct
66 Correct 112 ms 28088 KB Output is correct
67 Correct 416 ms 47660 KB Output is correct
68 Correct 411 ms 48164 KB Output is correct
69 Correct 12 ms 12884 KB Output is correct
70 Correct 70 ms 21412 KB Output is correct
71 Correct 255 ms 42328 KB Output is correct
72 Correct 278 ms 41144 KB Output is correct
73 Correct 80 ms 19244 KB Output is correct
74 Correct 343 ms 38108 KB Output is correct
75 Correct 24 ms 15296 KB Output is correct
76 Correct 255 ms 42080 KB Output is correct
77 Correct 273 ms 42160 KB Output is correct
78 Correct 27 ms 15564 KB Output is correct
79 Correct 404 ms 45540 KB Output is correct
80 Correct 7 ms 12244 KB Output is correct
81 Correct 84 ms 21404 KB Output is correct
82 Correct 321 ms 40000 KB Output is correct
83 Correct 387 ms 38148 KB Output is correct
84 Correct 351 ms 38112 KB Output is correct
85 Correct 360 ms 38084 KB Output is correct
86 Correct 345 ms 39260 KB Output is correct
87 Correct 365 ms 39272 KB Output is correct