Submission #605113

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
605113	2022-07-25T13:08:09 Z	tamthegod	Network (BOI15_net)	C++14	100 / 100	467 ms	68408 KB

#include<bits/stdc++.h>

#define int long long
#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 1e6 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
int n;
vector<int> adj[maxN];
int depth[maxN];
vector<int> leaf;
void ReadInput()
{
    cin >> n;
    for(int i=1; i<n; i++)
    {
        int u, v;
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
}
void dfs(int u, int par)
{
    if(adj[u].size() == 1) leaf.pb(u);
    for(int v : adj[u])
    {
        if(v == par) continue;
        depth[v] = depth[u] + 1;
        dfs(v, u);
    }
}
void Solve()
{
    dfs(1, 0);
    int l = 0, step = leaf.size() / 2;
    if(leaf.size() % 2 == 0)
    {
        cout << leaf.size() / 2 << '\n';
        while(l + step < leaf.size())
        {
            cout << leaf[l] << " " << leaf[l + step] << '\n';
            l++;
        }
        return;
    }
    leaf.pb(leaf[0]);
    step++;
    cout << leaf.size() / 2 << '\n';
    while(l + step < leaf.size())
    {
        cout << leaf[l] << " " << leaf[l + step] << '\n';
        l++;
    }
}
int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ReadInput();
    Solve();
}

Compilation message

net.cpp: In function 'void Solve()':
net.cpp:47:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         while(l + step < leaf.size())
      |               ~~~~~~~~~^~~~~~~~~~~~~
net.cpp:57:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     while(l + step < leaf.size())
      |           ~~~~~~~~~^~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	23764 KB	Output is correct
2	Correct	12 ms	23732 KB	Output is correct
3	Correct	12 ms	23764 KB	Output is correct
4	Correct	12 ms	23812 KB	Output is correct
5	Correct	14 ms	23816 KB	Output is correct
6	Correct	12 ms	23764 KB	Output is correct
7	Correct	12 ms	23812 KB	Output is correct
8	Correct	11 ms	23708 KB	Output is correct
9	Correct	15 ms	23712 KB	Output is correct
10	Correct	14 ms	23776 KB	Output is correct
11	Correct	14 ms	23764 KB	Output is correct
12	Correct	12 ms	23816 KB	Output is correct
13	Correct	12 ms	23748 KB	Output is correct
14	Correct	12 ms	23764 KB	Output is correct
15	Correct	12 ms	23764 KB	Output is correct
16	Correct	12 ms	23764 KB	Output is correct
17	Correct	12 ms	23820 KB	Output is correct
18	Correct	13 ms	23764 KB	Output is correct
19	Correct	12 ms	23792 KB	Output is correct
20	Correct	12 ms	23788 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	23764 KB	Output is correct
2	Correct	12 ms	23732 KB	Output is correct
3	Correct	12 ms	23764 KB	Output is correct
4	Correct	12 ms	23812 KB	Output is correct
5	Correct	14 ms	23816 KB	Output is correct
6	Correct	12 ms	23764 KB	Output is correct
7	Correct	12 ms	23812 KB	Output is correct
8	Correct	11 ms	23708 KB	Output is correct
9	Correct	15 ms	23712 KB	Output is correct
10	Correct	14 ms	23776 KB	Output is correct
11	Correct	14 ms	23764 KB	Output is correct
12	Correct	12 ms	23816 KB	Output is correct
13	Correct	12 ms	23748 KB	Output is correct
14	Correct	12 ms	23764 KB	Output is correct
15	Correct	12 ms	23764 KB	Output is correct
16	Correct	12 ms	23764 KB	Output is correct
17	Correct	12 ms	23820 KB	Output is correct
18	Correct	13 ms	23764 KB	Output is correct
19	Correct	12 ms	23792 KB	Output is correct
20	Correct	12 ms	23788 KB	Output is correct
21	Correct	14 ms	23764 KB	Output is correct
22	Correct	13 ms	23956 KB	Output is correct
23	Correct	15 ms	23892 KB	Output is correct
24	Correct	13 ms	23964 KB	Output is correct
25	Correct	13 ms	23880 KB	Output is correct
26	Correct	13 ms	23892 KB	Output is correct
27	Correct	13 ms	23960 KB	Output is correct
28	Correct	13 ms	23920 KB	Output is correct
29	Correct	13 ms	23924 KB	Output is correct
30	Correct	13 ms	23772 KB	Output is correct
31	Correct	15 ms	23876 KB	Output is correct
32	Correct	13 ms	23828 KB	Output is correct
33	Correct	15 ms	23772 KB	Output is correct
34	Correct	12 ms	23872 KB	Output is correct
35	Correct	13 ms	23764 KB	Output is correct
36	Correct	12 ms	23728 KB	Output is correct
37	Correct	13 ms	23876 KB	Output is correct
38	Correct	12 ms	23892 KB	Output is correct
39	Correct	12 ms	23764 KB	Output is correct
40	Correct	13 ms	23712 KB	Output is correct
41	Correct	12 ms	23732 KB	Output is correct
42	Correct	13 ms	23764 KB	Output is correct
43	Correct	13 ms	23828 KB	Output is correct
44	Correct	12 ms	23824 KB	Output is correct
45	Correct	13 ms	23812 KB	Output is correct
46	Correct	13 ms	23844 KB	Output is correct
47	Correct	12 ms	23764 KB	Output is correct
48	Correct	12 ms	23840 KB	Output is correct
49	Correct	12 ms	23788 KB	Output is correct
50	Correct	12 ms	23764 KB	Output is correct
51	Correct	13 ms	23764 KB	Output is correct
52	Correct	15 ms	23764 KB	Output is correct
53	Correct	12 ms	23828 KB	Output is correct
54	Correct	13 ms	23764 KB	Output is correct
55	Correct	13 ms	23828 KB	Output is correct
56	Correct	13 ms	23712 KB	Output is correct
57	Correct	16 ms	23764 KB	Output is correct
58	Correct	16 ms	23892 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	23764 KB	Output is correct
2	Correct	12 ms	23732 KB	Output is correct
3	Correct	12 ms	23764 KB	Output is correct
4	Correct	12 ms	23812 KB	Output is correct
5	Correct	14 ms	23816 KB	Output is correct
6	Correct	12 ms	23764 KB	Output is correct
7	Correct	12 ms	23812 KB	Output is correct
8	Correct	11 ms	23708 KB	Output is correct
9	Correct	15 ms	23712 KB	Output is correct
10	Correct	14 ms	23776 KB	Output is correct
11	Correct	14 ms	23764 KB	Output is correct
12	Correct	12 ms	23816 KB	Output is correct
13	Correct	12 ms	23748 KB	Output is correct
14	Correct	12 ms	23764 KB	Output is correct
15	Correct	12 ms	23764 KB	Output is correct
16	Correct	12 ms	23764 KB	Output is correct
17	Correct	12 ms	23820 KB	Output is correct
18	Correct	13 ms	23764 KB	Output is correct
19	Correct	12 ms	23792 KB	Output is correct
20	Correct	12 ms	23788 KB	Output is correct
21	Correct	14 ms	23764 KB	Output is correct
22	Correct	13 ms	23956 KB	Output is correct
23	Correct	15 ms	23892 KB	Output is correct
24	Correct	13 ms	23964 KB	Output is correct
25	Correct	13 ms	23880 KB	Output is correct
26	Correct	13 ms	23892 KB	Output is correct
27	Correct	13 ms	23960 KB	Output is correct
28	Correct	13 ms	23920 KB	Output is correct
29	Correct	13 ms	23924 KB	Output is correct
30	Correct	13 ms	23772 KB	Output is correct
31	Correct	15 ms	23876 KB	Output is correct
32	Correct	13 ms	23828 KB	Output is correct
33	Correct	15 ms	23772 KB	Output is correct
34	Correct	12 ms	23872 KB	Output is correct
35	Correct	13 ms	23764 KB	Output is correct
36	Correct	12 ms	23728 KB	Output is correct
37	Correct	13 ms	23876 KB	Output is correct
38	Correct	12 ms	23892 KB	Output is correct
39	Correct	12 ms	23764 KB	Output is correct
40	Correct	13 ms	23712 KB	Output is correct
41	Correct	12 ms	23732 KB	Output is correct
42	Correct	13 ms	23764 KB	Output is correct
43	Correct	13 ms	23828 KB	Output is correct
44	Correct	12 ms	23824 KB	Output is correct
45	Correct	13 ms	23812 KB	Output is correct
46	Correct	13 ms	23844 KB	Output is correct
47	Correct	12 ms	23764 KB	Output is correct
48	Correct	12 ms	23840 KB	Output is correct
49	Correct	12 ms	23788 KB	Output is correct
50	Correct	12 ms	23764 KB	Output is correct
51	Correct	13 ms	23764 KB	Output is correct
52	Correct	15 ms	23764 KB	Output is correct
53	Correct	12 ms	23828 KB	Output is correct
54	Correct	13 ms	23764 KB	Output is correct
55	Correct	13 ms	23828 KB	Output is correct
56	Correct	13 ms	23712 KB	Output is correct
57	Correct	16 ms	23764 KB	Output is correct
58	Correct	16 ms	23892 KB	Output is correct
59	Correct	307 ms	55812 KB	Output is correct
60	Correct	374 ms	59140 KB	Output is correct
61	Correct	12 ms	23824 KB	Output is correct
62	Correct	15 ms	23732 KB	Output is correct
63	Correct	302 ms	51628 KB	Output is correct
64	Correct	13 ms	24276 KB	Output is correct
65	Correct	20 ms	26140 KB	Output is correct
66	Correct	138 ms	43852 KB	Output is correct
67	Correct	430 ms	66708 KB	Output is correct
68	Correct	446 ms	68408 KB	Output is correct
69	Correct	19 ms	24988 KB	Output is correct
70	Correct	106 ms	36256 KB	Output is correct
71	Correct	279 ms	61436 KB	Output is correct
72	Correct	307 ms	59892 KB	Output is correct
73	Correct	105 ms	32924 KB	Output is correct
74	Correct	384 ms	57012 KB	Output is correct
75	Correct	34 ms	27788 KB	Output is correct
76	Correct	258 ms	60912 KB	Output is correct
77	Correct	259 ms	61208 KB	Output is correct
78	Correct	34 ms	28116 KB	Output is correct
79	Correct	467 ms	64444 KB	Output is correct
80	Correct	14 ms	24020 KB	Output is correct
81	Correct	106 ms	35660 KB	Output is correct
82	Correct	322 ms	58908 KB	Output is correct
83	Correct	390 ms	56812 KB	Output is correct
84	Correct	393 ms	56872 KB	Output is correct
85	Correct	393 ms	56956 KB	Output is correct
86	Correct	366 ms	59072 KB	Output is correct
87	Correct	408 ms	59052 KB	Output is correct

Submission #605113

Compilation message

Subtask #1 18.0 / 18.0

Subtask #2 45.0 / 45.0

Subtask #3 37.0 / 37.0

Subtask #1
18.0 / 18.0

Subtask #2
45.0 / 45.0

Subtask #3
37.0 / 37.0