oj.uz

Submission #643760

# Submission time Handle Problem Language Result Execution time Memory
643760 2022-09-23T01:10:56 Z ymm Network (BOI15_net) C++17
100 / 100
 837 ms 94692 KB 
#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;

const int N = 500'010;
vector<int> A[N];
int rt = 0;
int cnt[N];
int n;

int dfs1(int v, int p)
{
	cnt[v] = A[v].size() == 1;
	for (int u : A[v]) {
		if (u != p)
			cnt[v] += dfs1(u, v);
	}
	return cnt[v];
}

int dfs2(int v, int p, int tot)
{
	for (int u : A[v]) {
		if (u == p)
			continue;
		if (cnt[u] > tot - cnt[u])
			return dfs2(u, v, tot);
	}
	return v;
}

vector<int> leaves[N];

void dfs3(int v, int p, vector<int> &vec)
{
	if (A[v].size() == 1)
		vec.push_back(v);
	for (int u : A[v])
		if (u != p)
			dfs3(u, v, vec);
}

bool cmp(vector<int> *a, vector<int> *b) {
	return a->size() > b->size();
}

multiset<vector<int>*, bool (*)(vector<int>*, vector<int>*)> s(cmp);

int main()
{
	cin.tie(0) -> sync_with_stdio(false);
	cin >> n;
	Loop (i,1,n) {
		int v, u;
		cin >> v >> u;
		--v; --u;
		A[v].push_back(u);
		A[u].push_back(v);
	}
	while (A[rt].size() == 1) ++rt;
	dfs1(rt, -1);
	rt = dfs2(rt, -1, cnt[rt]);
	for (int v : A[rt]) {
		dfs3(v, rt, leaves[v]);
		s.insert(&leaves[v]);
	}
	vector<pii> ans;
	for (;;) {
		auto v1 = *s.begin();
		s.erase(s.begin());
		if (v1->size() == 0)
			break;
		auto v2 = *s.begin();
		s.erase(s.begin());
		if (v2->size() == 0) {
			ans.push_back({rt, v1->front()});
			break;
		}
		ans.push_back({v1->back(), v2->back()});
		v1->pop_back();
		v2->pop_back();
		s.insert(s.begin(), v1);
		s.insert(s.begin(), v2);
	}
	cout << ans.size() << '\n';
	for (auto [v, u] : ans)
		cout << v+1 << ' ' << u+1 << '\n';
}

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 23716 KB Output is correct
3 Correct 12 ms 23704 KB Output is correct
4 Correct 12 ms 23704 KB Output is correct
5 Correct 12 ms 23816 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 13 ms 23816 KB Output is correct
8 Correct 11 ms 23816 KB Output is correct
9 Correct 11 ms 23728 KB Output is correct
10 Correct 12 ms 23756 KB Output is correct
11 Correct 12 ms 23736 KB Output is correct
12 Correct 14 ms 23764 KB Output is correct
13 Correct 11 ms 23776 KB Output is correct
14 Correct 13 ms 23816 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23764 KB Output is correct
17 Correct 14 ms 23964 KB Output is correct
18 Correct 13 ms 23764 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 13 ms 23808 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 23716 KB Output is correct
3 Correct 12 ms 23704 KB Output is correct
4 Correct 12 ms 23704 KB Output is correct
5 Correct 12 ms 23816 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 13 ms 23816 KB Output is correct
8 Correct 11 ms 23816 KB Output is correct
9 Correct 11 ms 23728 KB Output is correct
10 Correct 12 ms 23756 KB Output is correct
11 Correct 12 ms 23736 KB Output is correct
12 Correct 14 ms 23764 KB Output is correct
13 Correct 11 ms 23776 KB Output is correct
14 Correct 13 ms 23816 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23764 KB Output is correct
17 Correct 14 ms 23964 KB Output is correct
18 Correct 13 ms 23764 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 13 ms 23808 KB Output is correct
21 Correct 12 ms 23704 KB Output is correct
22 Correct 15 ms 24020 KB Output is correct
23 Correct 16 ms 23952 KB Output is correct
24 Correct 13 ms 24020 KB Output is correct
25 Correct 13 ms 23912 KB Output is correct
26 Correct 14 ms 23832 KB Output is correct
27 Correct 14 ms 23828 KB Output is correct
28 Correct 15 ms 23892 KB Output is correct
29 Correct 13 ms 23836 KB Output is correct
30 Correct 12 ms 23800 KB Output is correct
31 Correct 12 ms 23892 KB Output is correct
32 Correct 12 ms 23764 KB Output is correct
33 Correct 14 ms 23812 KB Output is correct
34 Correct 12 ms 23764 KB Output is correct
35 Correct 12 ms 23764 KB Output is correct
36 Correct 13 ms 23764 KB Output is correct
37 Correct 13 ms 23764 KB Output is correct
38 Correct 13 ms 23892 KB Output is correct
39 Correct 11 ms 23764 KB Output is correct
40 Correct 12 ms 23808 KB Output is correct
41 Correct 12 ms 23760 KB Output is correct
42 Correct 12 ms 23764 KB Output is correct
43 Correct 13 ms 23944 KB Output is correct
44 Correct 12 ms 23744 KB Output is correct
45 Correct 13 ms 23812 KB Output is correct
46 Correct 13 ms 23820 KB Output is correct
47 Correct 11 ms 23772 KB Output is correct
48 Correct 13 ms 23824 KB Output is correct
49 Correct 14 ms 23892 KB Output is correct
50 Correct 11 ms 23764 KB Output is correct
51 Correct 12 ms 23812 KB Output is correct
52 Correct 12 ms 23800 KB Output is correct
53 Correct 14 ms 23820 KB Output is correct
54 Correct 13 ms 23816 KB Output is correct
55 Correct 16 ms 23764 KB Output is correct
56 Correct 15 ms 23696 KB Output is correct
57 Correct 13 ms 23860 KB Output is correct
58 Correct 15 ms 23836 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 23716 KB Output is correct
3 Correct 12 ms 23704 KB Output is correct
4 Correct 12 ms 23704 KB Output is correct
5 Correct 12 ms 23816 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 13 ms 23816 KB Output is correct
8 Correct 11 ms 23816 KB Output is correct
9 Correct 11 ms 23728 KB Output is correct
10 Correct 12 ms 23756 KB Output is correct
11 Correct 12 ms 23736 KB Output is correct
12 Correct 14 ms 23764 KB Output is correct
13 Correct 11 ms 23776 KB Output is correct
14 Correct 13 ms 23816 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23764 KB Output is correct
17 Correct 14 ms 23964 KB Output is correct
18 Correct 13 ms 23764 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 13 ms 23808 KB Output is correct
21 Correct 12 ms 23704 KB Output is correct
22 Correct 15 ms 24020 KB Output is correct
23 Correct 16 ms 23952 KB Output is correct
24 Correct 13 ms 24020 KB Output is correct
25 Correct 13 ms 23912 KB Output is correct
26 Correct 14 ms 23832 KB Output is correct
27 Correct 14 ms 23828 KB Output is correct
28 Correct 15 ms 23892 KB Output is correct
29 Correct 13 ms 23836 KB Output is correct
30 Correct 12 ms 23800 KB Output is correct
31 Correct 12 ms 23892 KB Output is correct
32 Correct 12 ms 23764 KB Output is correct
33 Correct 14 ms 23812 KB Output is correct
34 Correct 12 ms 23764 KB Output is correct
35 Correct 12 ms 23764 KB Output is correct
36 Correct 13 ms 23764 KB Output is correct
37 Correct 13 ms 23764 KB Output is correct
38 Correct 13 ms 23892 KB Output is correct
39 Correct 11 ms 23764 KB Output is correct
40 Correct 12 ms 23808 KB Output is correct
41 Correct 12 ms 23760 KB Output is correct
42 Correct 12 ms 23764 KB Output is correct
43 Correct 13 ms 23944 KB Output is correct
44 Correct 12 ms 23744 KB Output is correct
45 Correct 13 ms 23812 KB Output is correct
46 Correct 13 ms 23820 KB Output is correct
47 Correct 11 ms 23772 KB Output is correct
48 Correct 13 ms 23824 KB Output is correct
49 Correct 14 ms 23892 KB Output is correct
50 Correct 11 ms 23764 KB Output is correct
51 Correct 12 ms 23812 KB Output is correct
52 Correct 12 ms 23800 KB Output is correct
53 Correct 14 ms 23820 KB Output is correct
54 Correct 13 ms 23816 KB Output is correct
55 Correct 16 ms 23764 KB Output is correct
56 Correct 15 ms 23696 KB Output is correct
57 Correct 13 ms 23860 KB Output is correct
58 Correct 15 ms 23836 KB Output is correct
59 Correct 535 ms 61272 KB Output is correct
60 Correct 415 ms 54288 KB Output is correct
61 Correct 12 ms 23764 KB Output is correct
62 Correct 12 ms 23820 KB Output is correct
63 Correct 461 ms 54644 KB Output is correct
64 Correct 14 ms 24244 KB Output is correct
65 Correct 21 ms 26056 KB Output is correct
66 Correct 193 ms 43000 KB Output is correct
67 Correct 550 ms 64736 KB Output is correct
68 Correct 542 ms 65852 KB Output is correct
69 Correct 27 ms 25804 KB Output is correct
70 Correct 224 ms 44648 KB Output is correct
71 Correct 837 ms 94692 KB Output is correct
72 Correct 765 ms 89440 KB Output is correct
73 Correct 109 ms 31684 KB Output is correct
74 Correct 427 ms 52440 KB Output is correct
75 Correct 44 ms 29292 KB Output is correct
76 Correct 479 ms 74920 KB Output is correct
77 Correct 538 ms 75860 KB Output is correct
78 Correct 36 ms 27852 KB Output is correct
79 Correct 526 ms 62496 KB Output is correct
80 Correct 14 ms 24148 KB Output is correct
81 Correct 223 ms 40408 KB Output is correct
82 Correct 612 ms 73320 KB Output is correct
83 Correct 424 ms 52364 KB Output is correct
84 Correct 481 ms 52828 KB Output is correct
85 Correct 472 ms 52744 KB Output is correct
86 Correct 435 ms 54688 KB Output is correct
87 Correct 465 ms 54608 KB Output is correct