답안 #108707

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
108707	2019-05-01T06:08:12 Z	MAMBA	Network (BOI15_net)	C++17	100 / 100	769 ms	80720 KB

#include <bits/stdc++.h> 

using namespace std;

#define rep(i , j , k) for (int i = j; i < k; i++)
#define pb push_back
#define for_all(x) x.begin(),x.end()

typedef long long ll;
typedef pair<int , int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

inline void fileIO(string s) {
	freopen((s + ".in").c_str(), "r", stdin);
	freopen((s + ".out").c_str(), "w", stdout);
}

template<class T , class S>
inline void smin(T &a, S b) {
	if (a > b)
		a = b;
}

template<class T , class S>
inline void smax(T &a, S b) {
	if (a < b)
		a = b;
}

constexpr int N = 1e6 + 10;

int n;
vi adj[N];
vector<pii> res;
pii dp[N];

void dfs(int v, int par = 0) {
	vi st;
	if (adj[v].size() == 1) {
		dp[v] = {v , -1};
		return;
	}
	for (auto e : adj[v])
		if (e ^ par) {
			dfs(e, v);
			if (st.size() > 1) {
				res.pb({st.back() , dp[e].first});
				st.pop_back();
				dp[e].first = -1;
			}
			if (st.size() > 1 && dp[e].second != -1) {
				res.pb({st.back() , dp[e].second});
				st.pop_back();
				dp[e].second = -1;
			}
			if (dp[e].first != -1)
				st.pb(dp[e].first);
			if (dp[e].second != -1)
				st.pb(dp[e].second);
		}
	if (st.size() == 3) {
		res.pb({st[0] , st[1]});
		int me = st.back();
		st.clear();
		st.pb(me);
	}
	dp[v].first = st.back();
	st.pop_back();
	dp[v].second = st.empty() ? -1 : st.back();

}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	cin >> n;
	rep(i , 1 , n) {
		int u , v;
		cin >> u >> v;
		adj[u].pb(v);
		adj[v].pb(u);
	}

	rep(i , 1 , n + 1)
		if (adj[i].size() > 1) {
			dfs(i);
			if (dp[i].first != -1 && dp[i].second != -1) 
				res.pb(dp[i]);
			else
				res.pb({dp[i].first , i});
			break;
		}

	cout << res.size() << endl;
	for (auto e : res)
		cout <<e.first << ' ' << e.second << '\n';


	return 0;
}

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	23 ms	23780 KB	Output is correct
2	Correct	25 ms	23780 KB	Output is correct
3	Correct	24 ms	23808 KB	Output is correct
4	Correct	24 ms	23808 KB	Output is correct
5	Correct	24 ms	23800 KB	Output is correct
6	Correct	25 ms	23824 KB	Output is correct
7	Correct	22 ms	23808 KB	Output is correct
8	Correct	24 ms	23808 KB	Output is correct
9	Correct	26 ms	23780 KB	Output is correct
10	Correct	24 ms	23860 KB	Output is correct
11	Correct	24 ms	23780 KB	Output is correct
12	Correct	26 ms	23780 KB	Output is correct
13	Correct	29 ms	23800 KB	Output is correct
14	Correct	24 ms	23800 KB	Output is correct
15	Correct	27 ms	23800 KB	Output is correct
16	Correct	26 ms	23808 KB	Output is correct
17	Correct	23 ms	23808 KB	Output is correct
18	Correct	24 ms	23808 KB	Output is correct
19	Correct	25 ms	23800 KB	Output is correct
20	Correct	24 ms	23800 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	23 ms	23780 KB	Output is correct
2	Correct	25 ms	23780 KB	Output is correct
3	Correct	24 ms	23808 KB	Output is correct
4	Correct	24 ms	23808 KB	Output is correct
5	Correct	24 ms	23800 KB	Output is correct
6	Correct	25 ms	23824 KB	Output is correct
7	Correct	22 ms	23808 KB	Output is correct
8	Correct	24 ms	23808 KB	Output is correct
9	Correct	26 ms	23780 KB	Output is correct
10	Correct	24 ms	23860 KB	Output is correct
11	Correct	24 ms	23780 KB	Output is correct
12	Correct	26 ms	23780 KB	Output is correct
13	Correct	29 ms	23800 KB	Output is correct
14	Correct	24 ms	23800 KB	Output is correct
15	Correct	27 ms	23800 KB	Output is correct
16	Correct	26 ms	23808 KB	Output is correct
17	Correct	23 ms	23808 KB	Output is correct
18	Correct	24 ms	23808 KB	Output is correct
19	Correct	25 ms	23800 KB	Output is correct
20	Correct	24 ms	23800 KB	Output is correct
21	Correct	25 ms	23772 KB	Output is correct
22	Correct	25 ms	23928 KB	Output is correct
23	Correct	29 ms	23928 KB	Output is correct
24	Correct	27 ms	24072 KB	Output is correct
25	Correct	25 ms	23936 KB	Output is correct
26	Correct	53 ms	23928 KB	Output is correct
27	Correct	27 ms	23932 KB	Output is correct
28	Correct	25 ms	23928 KB	Output is correct
29	Correct	29 ms	23944 KB	Output is correct
30	Correct	26 ms	23808 KB	Output is correct
31	Correct	29 ms	23936 KB	Output is correct
32	Correct	25 ms	23808 KB	Output is correct
33	Correct	26 ms	23816 KB	Output is correct
34	Correct	26 ms	23888 KB	Output is correct
35	Correct	23 ms	23800 KB	Output is correct
36	Correct	25 ms	23780 KB	Output is correct
37	Correct	25 ms	23928 KB	Output is correct
38	Correct	26 ms	23936 KB	Output is correct
39	Correct	25 ms	23780 KB	Output is correct
40	Correct	25 ms	23808 KB	Output is correct
41	Correct	25 ms	23808 KB	Output is correct
42	Correct	27 ms	23800 KB	Output is correct
43	Correct	30 ms	23864 KB	Output is correct
44	Correct	25 ms	23808 KB	Output is correct
45	Correct	27 ms	23836 KB	Output is correct
46	Correct	25 ms	23808 KB	Output is correct
47	Correct	24 ms	23808 KB	Output is correct
48	Correct	25 ms	23804 KB	Output is correct
49	Correct	24 ms	23936 KB	Output is correct
50	Correct	24 ms	23800 KB	Output is correct
51	Correct	28 ms	23800 KB	Output is correct
52	Correct	27 ms	24064 KB	Output is correct
53	Correct	25 ms	23876 KB	Output is correct
54	Correct	24 ms	23808 KB	Output is correct
55	Correct	24 ms	23808 KB	Output is correct
56	Correct	24 ms	23856 KB	Output is correct
57	Correct	25 ms	23808 KB	Output is correct
58	Correct	24 ms	23928 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	23 ms	23780 KB	Output is correct
2	Correct	25 ms	23780 KB	Output is correct
3	Correct	24 ms	23808 KB	Output is correct
4	Correct	24 ms	23808 KB	Output is correct
5	Correct	24 ms	23800 KB	Output is correct
6	Correct	25 ms	23824 KB	Output is correct
7	Correct	22 ms	23808 KB	Output is correct
8	Correct	24 ms	23808 KB	Output is correct
9	Correct	26 ms	23780 KB	Output is correct
10	Correct	24 ms	23860 KB	Output is correct
11	Correct	24 ms	23780 KB	Output is correct
12	Correct	26 ms	23780 KB	Output is correct
13	Correct	29 ms	23800 KB	Output is correct
14	Correct	24 ms	23800 KB	Output is correct
15	Correct	27 ms	23800 KB	Output is correct
16	Correct	26 ms	23808 KB	Output is correct
17	Correct	23 ms	23808 KB	Output is correct
18	Correct	24 ms	23808 KB	Output is correct
19	Correct	25 ms	23800 KB	Output is correct
20	Correct	24 ms	23800 KB	Output is correct
21	Correct	25 ms	23772 KB	Output is correct
22	Correct	25 ms	23928 KB	Output is correct
23	Correct	29 ms	23928 KB	Output is correct
24	Correct	27 ms	24072 KB	Output is correct
25	Correct	25 ms	23936 KB	Output is correct
26	Correct	53 ms	23928 KB	Output is correct
27	Correct	27 ms	23932 KB	Output is correct
28	Correct	25 ms	23928 KB	Output is correct
29	Correct	29 ms	23944 KB	Output is correct
30	Correct	26 ms	23808 KB	Output is correct
31	Correct	29 ms	23936 KB	Output is correct
32	Correct	25 ms	23808 KB	Output is correct
33	Correct	26 ms	23816 KB	Output is correct
34	Correct	26 ms	23888 KB	Output is correct
35	Correct	23 ms	23800 KB	Output is correct
36	Correct	25 ms	23780 KB	Output is correct
37	Correct	25 ms	23928 KB	Output is correct
38	Correct	26 ms	23936 KB	Output is correct
39	Correct	25 ms	23780 KB	Output is correct
40	Correct	25 ms	23808 KB	Output is correct
41	Correct	25 ms	23808 KB	Output is correct
42	Correct	27 ms	23800 KB	Output is correct
43	Correct	30 ms	23864 KB	Output is correct
44	Correct	25 ms	23808 KB	Output is correct
45	Correct	27 ms	23836 KB	Output is correct
46	Correct	25 ms	23808 KB	Output is correct
47	Correct	24 ms	23808 KB	Output is correct
48	Correct	25 ms	23804 KB	Output is correct
49	Correct	24 ms	23936 KB	Output is correct
50	Correct	24 ms	23800 KB	Output is correct
51	Correct	28 ms	23800 KB	Output is correct
52	Correct	27 ms	24064 KB	Output is correct
53	Correct	25 ms	23876 KB	Output is correct
54	Correct	24 ms	23808 KB	Output is correct
55	Correct	24 ms	23808 KB	Output is correct
56	Correct	24 ms	23856 KB	Output is correct
57	Correct	25 ms	23808 KB	Output is correct
58	Correct	24 ms	23928 KB	Output is correct
59	Correct	598 ms	51492 KB	Output is correct
60	Correct	662 ms	54560 KB	Output is correct
61	Correct	23 ms	23800 KB	Output is correct
62	Correct	24 ms	23808 KB	Output is correct
63	Correct	454 ms	48488 KB	Output is correct
64	Correct	31 ms	24568 KB	Output is correct
65	Correct	51 ms	27000 KB	Output is correct
66	Correct	260 ms	51752 KB	Output is correct
67	Correct	769 ms	79484 KB	Output is correct
68	Correct	751 ms	80720 KB	Output is correct
69	Correct	32 ms	24824 KB	Output is correct
70	Correct	162 ms	34436 KB	Output is correct
71	Correct	448 ms	57696 KB	Output is correct
72	Correct	405 ms	56416 KB	Output is correct
73	Correct	171 ms	31988 KB	Output is correct
74	Correct	653 ms	53484 KB	Output is correct
75	Correct	81 ms	27512 KB	Output is correct
76	Correct	416 ms	57216 KB	Output is correct
77	Correct	424 ms	57364 KB	Output is correct
78	Correct	65 ms	29048 KB	Output is correct
79	Correct	717 ms	75464 KB	Output is correct
80	Correct	29 ms	24064 KB	Output is correct
81	Correct	170 ms	34412 KB	Output is correct
82	Correct	617 ms	55232 KB	Output is correct
83	Correct	656 ms	53468 KB	Output is correct
84	Correct	663 ms	53380 KB	Output is correct
85	Correct	676 ms	53492 KB	Output is correct
86	Correct	621 ms	54412 KB	Output is correct
87	Correct	609 ms	54420 KB	Output is correct

답안 #108707

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