oj.uz

Submission #632577

# Submission time Handle Problem Language Result Execution time Memory
632577 2022-08-20T10:57:19 Z stevancv Network (BOI15_net) C++14
100 / 100
 579 ms 77144 KB 
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 5e5 + 2;
const int mod = 1e9 + 7;
vector<int> g[N];
int szl[N];
vector<vector<int>> all;
void Dfs(int s, int e) {
    for (int u : g[s]) {
        if (u != e) {
            Dfs(u, s);
            szl[s] += szl[u];
        }
    }
    smax(szl[s], 1);
}
int Dfs1(int s, int e, int t) {
    for (int u : g[s]) {
        if (u == e) continue;
        if (2 * szl[u] > t) return Dfs1(u, s, t);
    }
    return s;
}
void Dfs2(int s, int e, int r) {
    if (g[s].size() == 1) all.back().push_back(s);
    for (int u : g[s]) {
        if (u == e) continue;
        if (s == r) all.push_back({});
        Dfs2(u, s, r);
    }
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    for (int i = 0; i < n - 1; i++) {
        int u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int root = 1;
    for (int i = 1; i <= n; i++) if (g[i].size() > g[root].size()) root = i;
    Dfs(root, 0);
    root = Dfs1(root, 0, szl[root]);
    Dfs2(root, 0, root);
    int sz = all.size();
    priority_queue<pair<int, int>> pq;
    vector<array<int, 2>> ans;
    for (int i = 0; i < sz; i++) pq.push({all[i].size(), i});
    int who = -1;
    while (pq.size() > 1) {
        int x = pq.top().second; pq.pop();
        int y = pq.top().second; pq.pop();
        who = all[x].back();
        ans.push_back({all[x].back(), all[y].back()});
        all[x].pop_back(); all[y].pop_back();
        if (all[x].size() > 0) pq.push({all[x].size(), x});
        if (all[y].size() > 0) pq.push({all[y].size(), y});
    }
    if (pq.size() == 1) ans.push_back({who, all[pq.top().second].back()});
    cout << ans.size() << en;
    for (int i = 0; i < ans.size(); i++) {
        cout << ans[i][0] << sp << ans[i][1] << en;
    }
    return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:70:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for (int i = 0; i < ans.size(); i++) {
      |                     ~~^~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11992 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 12080 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 12056 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 7 ms 11956 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 7 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 6 ms 12028 KB Output is correct
17 Correct 6 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 8 ms 12072 KB Output is correct
20 Correct 6 ms 12052 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 6 ms 11988 KB Output is correct
3 Correct 6 ms 11992 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 12080 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 12056 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 7 ms 11956 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 7 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 6 ms 12028 KB Output is correct
17 Correct 6 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 8 ms 12072 KB Output is correct
20 Correct 6 ms 12052 KB Output is correct
21 Correct 7 ms 11988 KB Output is correct
22 Correct 7 ms 12192 KB Output is correct
23 Correct 7 ms 12340 KB Output is correct
24 Correct 7 ms 12244 KB Output is correct
25 Correct 7 ms 12116 KB Output is correct
26 Correct 8 ms 12116 KB Output is correct
27 Correct 7 ms 12084 KB Output is correct
28 Correct 7 ms 12080 KB Output is correct
29 Correct 6 ms 12116 KB Output is correct
30 Correct 7 ms 11988 KB Output is correct
31 Correct 9 ms 12084 KB Output is correct
32 Correct 6 ms 11988 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 7 ms 12008 KB Output is correct
35 Correct 6 ms 12020 KB Output is correct
36 Correct 6 ms 11988 KB Output is correct
37 Correct 6 ms 12076 KB Output is correct
38 Correct 7 ms 12092 KB Output is correct
39 Correct 6 ms 11988 KB Output is correct
40 Correct 6 ms 11988 KB Output is correct
41 Correct 6 ms 11988 KB Output is correct
42 Correct 6 ms 12072 KB Output is correct
43 Correct 7 ms 12204 KB Output is correct
44 Correct 8 ms 11988 KB Output is correct
45 Correct 6 ms 12072 KB Output is correct
46 Correct 6 ms 12072 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 11988 KB Output is correct
49 Correct 7 ms 12060 KB Output is correct
50 Correct 6 ms 11988 KB Output is correct
51 Correct 6 ms 11988 KB Output is correct
52 Correct 6 ms 11988 KB Output is correct
53 Correct 6 ms 12116 KB Output is correct
54 Correct 6 ms 12072 KB Output is correct
55 Correct 6 ms 12076 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 7 ms 12116 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 6 ms 11988 KB Output is correct
3 Correct 6 ms 11992 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 12080 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 12056 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 7 ms 11956 KB Output is correct
12 Correct 6 ms 11988 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 7 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 6 ms 12028 KB Output is correct
17 Correct 6 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 8 ms 12072 KB Output is correct
20 Correct 6 ms 12052 KB Output is correct
21 Correct 7 ms 11988 KB Output is correct
22 Correct 7 ms 12192 KB Output is correct
23 Correct 7 ms 12340 KB Output is correct
24 Correct 7 ms 12244 KB Output is correct
25 Correct 7 ms 12116 KB Output is correct
26 Correct 8 ms 12116 KB Output is correct
27 Correct 7 ms 12084 KB Output is correct
28 Correct 7 ms 12080 KB Output is correct
29 Correct 6 ms 12116 KB Output is correct
30 Correct 7 ms 11988 KB Output is correct
31 Correct 9 ms 12084 KB Output is correct
32 Correct 6 ms 11988 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 7 ms 12008 KB Output is correct
35 Correct 6 ms 12020 KB Output is correct
36 Correct 6 ms 11988 KB Output is correct
37 Correct 6 ms 12076 KB Output is correct
38 Correct 7 ms 12092 KB Output is correct
39 Correct 6 ms 11988 KB Output is correct
40 Correct 6 ms 11988 KB Output is correct
41 Correct 6 ms 11988 KB Output is correct
42 Correct 6 ms 12072 KB Output is correct
43 Correct 7 ms 12204 KB Output is correct
44 Correct 8 ms 11988 KB Output is correct
45 Correct 6 ms 12072 KB Output is correct
46 Correct 6 ms 12072 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 11988 KB Output is correct
49 Correct 7 ms 12060 KB Output is correct
50 Correct 6 ms 11988 KB Output is correct
51 Correct 6 ms 11988 KB Output is correct
52 Correct 6 ms 11988 KB Output is correct
53 Correct 6 ms 12116 KB Output is correct
54 Correct 6 ms 12072 KB Output is correct
55 Correct 6 ms 12076 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 7 ms 12116 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct
59 Correct 428 ms 49096 KB Output is correct
60 Correct 420 ms 42500 KB Output is correct
61 Correct 6 ms 12072 KB Output is correct
62 Correct 6 ms 11988 KB Output is correct
63 Correct 342 ms 43324 KB Output is correct
64 Correct 8 ms 12500 KB Output is correct
65 Correct 15 ms 14420 KB Output is correct
66 Correct 144 ms 31180 KB Output is correct
67 Correct 526 ms 65576 KB Output is correct
68 Correct 579 ms 72244 KB Output is correct
69 Correct 14 ms 13840 KB Output is correct
70 Correct 101 ms 32036 KB Output is correct
71 Correct 359 ms 77144 KB Output is correct
72 Correct 389 ms 72848 KB Output is correct
73 Correct 79 ms 19932 KB Output is correct
74 Correct 432 ms 40656 KB Output is correct
75 Correct 31 ms 17300 KB Output is correct
76 Correct 381 ms 61444 KB Output is correct
77 Correct 366 ms 62080 KB Output is correct
78 Correct 32 ms 16664 KB Output is correct
79 Correct 512 ms 54588 KB Output is correct
80 Correct 8 ms 12340 KB Output is correct
81 Correct 110 ms 27784 KB Output is correct
82 Correct 442 ms 59520 KB Output is correct
83 Correct 425 ms 40840 KB Output is correct
84 Correct 420 ms 41172 KB Output is correct
85 Correct 420 ms 41156 KB Output is correct
86 Correct 407 ms 42880 KB Output is correct
87 Correct 396 ms 42920 KB Output is correct