# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
656126 |
2022-11-06T10:21:28 Z |
Kahou |
Network (BOI15_net) |
C++14 |
|
557 ms |
90312 KB |
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 5e5 + 50;
int n, sub[N], k, par[N], t;
vector<int> adj[N];
vector<int> vc[N];
set<pii> st;
vector<pii> out;
void dfs(int u, int p) {
par[u] = p;
for (int v:adj[u]) {
if (v == p) continue;
dfs(v, u);
sub[u] += sub[v];
}
}
void dfs2(int u, int p) {
if (adj[u].size() == 1) {
vc[t].push_back(u);
}
for (int v:adj[u]) {
if (v == p) continue;
dfs2(v, u);
}
}
void solve() {
cin >> n;
for (int i = 1; i <= n-1; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int u = 1; u <= n; u++) {
if (adj[u].size() == 1) {
k++;
sub[u] = 1;
}
}
dfs(1, 0);
int r = 0;
for (int u = 1; u <= n; u++) {
if (adj[u].size() == 1) continue;
bool flg = 1;
for (int v:adj[u]) {
if (v == par[u]) flg = flg&&(k-sub[u] <= k/2);
else flg = flg&&(sub[v] <= k/2);
}
if (flg) {
r = u;
break;
}
}
for (int u:adj[r]) {
t++;
dfs2(u, r);
}
for (int i = 1; i <= t; i++) {
st.insert({-vc[i].size(), i});
}
while (st.size() >= 2) {
auto it = st.begin();
int A = it->S; it++;
int B = it->S;
out.push_back({vc[A].back(), vc[B].back()});
st.erase({-vc[A].size(), A});
st.erase({-vc[B].size(), B});
vc[A].pop_back();
vc[B].pop_back();
if (!vc[A].empty()) st.insert({-vc[A].size(), A});
if (!vc[B].empty()) st.insert({-vc[B].size(), B});
}
if (st.size()) {
int A = st.begin()->S;
int u = vc[A].back();
out.push_back({u, r});
}
cout << out.size() << endl;
for (pii x:out) {
cout << x.F << ' ' << x.S << endl;
}
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
23792 KB |
Output is correct |
2 |
Correct |
12 ms |
23764 KB |
Output is correct |
3 |
Correct |
13 ms |
23764 KB |
Output is correct |
4 |
Correct |
12 ms |
23764 KB |
Output is correct |
5 |
Correct |
12 ms |
23776 KB |
Output is correct |
6 |
Correct |
13 ms |
23764 KB |
Output is correct |
7 |
Correct |
13 ms |
23740 KB |
Output is correct |
8 |
Correct |
12 ms |
23764 KB |
Output is correct |
9 |
Correct |
13 ms |
23796 KB |
Output is correct |
10 |
Correct |
12 ms |
23764 KB |
Output is correct |
11 |
Correct |
15 ms |
23844 KB |
Output is correct |
12 |
Correct |
13 ms |
23764 KB |
Output is correct |
13 |
Correct |
15 ms |
23816 KB |
Output is correct |
14 |
Correct |
13 ms |
23780 KB |
Output is correct |
15 |
Correct |
13 ms |
23824 KB |
Output is correct |
16 |
Correct |
12 ms |
23764 KB |
Output is correct |
17 |
Correct |
13 ms |
23764 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 |
23704 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
23792 KB |
Output is correct |
2 |
Correct |
12 ms |
23764 KB |
Output is correct |
3 |
Correct |
13 ms |
23764 KB |
Output is correct |
4 |
Correct |
12 ms |
23764 KB |
Output is correct |
5 |
Correct |
12 ms |
23776 KB |
Output is correct |
6 |
Correct |
13 ms |
23764 KB |
Output is correct |
7 |
Correct |
13 ms |
23740 KB |
Output is correct |
8 |
Correct |
12 ms |
23764 KB |
Output is correct |
9 |
Correct |
13 ms |
23796 KB |
Output is correct |
10 |
Correct |
12 ms |
23764 KB |
Output is correct |
11 |
Correct |
15 ms |
23844 KB |
Output is correct |
12 |
Correct |
13 ms |
23764 KB |
Output is correct |
13 |
Correct |
15 ms |
23816 KB |
Output is correct |
14 |
Correct |
13 ms |
23780 KB |
Output is correct |
15 |
Correct |
13 ms |
23824 KB |
Output is correct |
16 |
Correct |
12 ms |
23764 KB |
Output is correct |
17 |
Correct |
13 ms |
23764 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 |
23704 KB |
Output is correct |
21 |
Correct |
14 ms |
23764 KB |
Output is correct |
22 |
Correct |
13 ms |
23892 KB |
Output is correct |
23 |
Correct |
13 ms |
23876 KB |
Output is correct |
24 |
Correct |
13 ms |
24020 KB |
Output is correct |
25 |
Correct |
13 ms |
23892 KB |
Output is correct |
26 |
Correct |
13 ms |
23892 KB |
Output is correct |
27 |
Correct |
14 ms |
23892 KB |
Output is correct |
28 |
Correct |
13 ms |
23892 KB |
Output is correct |
29 |
Correct |
13 ms |
23800 KB |
Output is correct |
30 |
Correct |
14 ms |
23764 KB |
Output is correct |
31 |
Correct |
13 ms |
23892 KB |
Output is correct |
32 |
Correct |
16 ms |
23764 KB |
Output is correct |
33 |
Correct |
13 ms |
23764 KB |
Output is correct |
34 |
Correct |
14 ms |
23764 KB |
Output is correct |
35 |
Correct |
15 ms |
23736 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 |
23820 KB |
Output is correct |
39 |
Correct |
12 ms |
23764 KB |
Output is correct |
40 |
Correct |
12 ms |
23720 KB |
Output is correct |
41 |
Correct |
13 ms |
23732 KB |
Output is correct |
42 |
Correct |
13 ms |
23764 KB |
Output is correct |
43 |
Correct |
13 ms |
23892 KB |
Output is correct |
44 |
Correct |
12 ms |
23764 KB |
Output is correct |
45 |
Correct |
13 ms |
23756 KB |
Output is correct |
46 |
Correct |
13 ms |
23784 KB |
Output is correct |
47 |
Correct |
14 ms |
23764 KB |
Output is correct |
48 |
Correct |
12 ms |
23764 KB |
Output is correct |
49 |
Correct |
13 ms |
23892 KB |
Output is correct |
50 |
Correct |
13 ms |
23820 KB |
Output is correct |
51 |
Correct |
12 ms |
23764 KB |
Output is correct |
52 |
Correct |
14 ms |
23812 KB |
Output is correct |
53 |
Correct |
13 ms |
23764 KB |
Output is correct |
54 |
Correct |
12 ms |
23764 KB |
Output is correct |
55 |
Correct |
15 ms |
23760 KB |
Output is correct |
56 |
Correct |
13 ms |
23724 KB |
Output is correct |
57 |
Correct |
13 ms |
23796 KB |
Output is correct |
58 |
Correct |
14 ms |
23900 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
23792 KB |
Output is correct |
2 |
Correct |
12 ms |
23764 KB |
Output is correct |
3 |
Correct |
13 ms |
23764 KB |
Output is correct |
4 |
Correct |
12 ms |
23764 KB |
Output is correct |
5 |
Correct |
12 ms |
23776 KB |
Output is correct |
6 |
Correct |
13 ms |
23764 KB |
Output is correct |
7 |
Correct |
13 ms |
23740 KB |
Output is correct |
8 |
Correct |
12 ms |
23764 KB |
Output is correct |
9 |
Correct |
13 ms |
23796 KB |
Output is correct |
10 |
Correct |
12 ms |
23764 KB |
Output is correct |
11 |
Correct |
15 ms |
23844 KB |
Output is correct |
12 |
Correct |
13 ms |
23764 KB |
Output is correct |
13 |
Correct |
15 ms |
23816 KB |
Output is correct |
14 |
Correct |
13 ms |
23780 KB |
Output is correct |
15 |
Correct |
13 ms |
23824 KB |
Output is correct |
16 |
Correct |
12 ms |
23764 KB |
Output is correct |
17 |
Correct |
13 ms |
23764 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 |
23704 KB |
Output is correct |
21 |
Correct |
14 ms |
23764 KB |
Output is correct |
22 |
Correct |
13 ms |
23892 KB |
Output is correct |
23 |
Correct |
13 ms |
23876 KB |
Output is correct |
24 |
Correct |
13 ms |
24020 KB |
Output is correct |
25 |
Correct |
13 ms |
23892 KB |
Output is correct |
26 |
Correct |
13 ms |
23892 KB |
Output is correct |
27 |
Correct |
14 ms |
23892 KB |
Output is correct |
28 |
Correct |
13 ms |
23892 KB |
Output is correct |
29 |
Correct |
13 ms |
23800 KB |
Output is correct |
30 |
Correct |
14 ms |
23764 KB |
Output is correct |
31 |
Correct |
13 ms |
23892 KB |
Output is correct |
32 |
Correct |
16 ms |
23764 KB |
Output is correct |
33 |
Correct |
13 ms |
23764 KB |
Output is correct |
34 |
Correct |
14 ms |
23764 KB |
Output is correct |
35 |
Correct |
15 ms |
23736 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 |
23820 KB |
Output is correct |
39 |
Correct |
12 ms |
23764 KB |
Output is correct |
40 |
Correct |
12 ms |
23720 KB |
Output is correct |
41 |
Correct |
13 ms |
23732 KB |
Output is correct |
42 |
Correct |
13 ms |
23764 KB |
Output is correct |
43 |
Correct |
13 ms |
23892 KB |
Output is correct |
44 |
Correct |
12 ms |
23764 KB |
Output is correct |
45 |
Correct |
13 ms |
23756 KB |
Output is correct |
46 |
Correct |
13 ms |
23784 KB |
Output is correct |
47 |
Correct |
14 ms |
23764 KB |
Output is correct |
48 |
Correct |
12 ms |
23764 KB |
Output is correct |
49 |
Correct |
13 ms |
23892 KB |
Output is correct |
50 |
Correct |
13 ms |
23820 KB |
Output is correct |
51 |
Correct |
12 ms |
23764 KB |
Output is correct |
52 |
Correct |
14 ms |
23812 KB |
Output is correct |
53 |
Correct |
13 ms |
23764 KB |
Output is correct |
54 |
Correct |
12 ms |
23764 KB |
Output is correct |
55 |
Correct |
15 ms |
23760 KB |
Output is correct |
56 |
Correct |
13 ms |
23724 KB |
Output is correct |
57 |
Correct |
13 ms |
23796 KB |
Output is correct |
58 |
Correct |
14 ms |
23900 KB |
Output is correct |
59 |
Correct |
457 ms |
58276 KB |
Output is correct |
60 |
Correct |
456 ms |
52080 KB |
Output is correct |
61 |
Correct |
13 ms |
23764 KB |
Output is correct |
62 |
Correct |
13 ms |
23764 KB |
Output is correct |
63 |
Correct |
394 ms |
52300 KB |
Output is correct |
64 |
Correct |
15 ms |
24348 KB |
Output is correct |
65 |
Correct |
24 ms |
26360 KB |
Output is correct |
66 |
Correct |
165 ms |
45532 KB |
Output is correct |
67 |
Correct |
534 ms |
66768 KB |
Output is correct |
68 |
Correct |
531 ms |
67896 KB |
Output is correct |
69 |
Correct |
22 ms |
25756 KB |
Output is correct |
70 |
Correct |
125 ms |
44064 KB |
Output is correct |
71 |
Correct |
472 ms |
90312 KB |
Output is correct |
72 |
Correct |
468 ms |
85668 KB |
Output is correct |
73 |
Correct |
99 ms |
32088 KB |
Output is correct |
74 |
Correct |
483 ms |
50160 KB |
Output is correct |
75 |
Correct |
41 ms |
29260 KB |
Output is correct |
76 |
Correct |
388 ms |
70688 KB |
Output is correct |
77 |
Correct |
421 ms |
71712 KB |
Output is correct |
78 |
Correct |
35 ms |
28108 KB |
Output is correct |
79 |
Correct |
557 ms |
63848 KB |
Output is correct |
80 |
Correct |
15 ms |
24148 KB |
Output is correct |
81 |
Correct |
130 ms |
40040 KB |
Output is correct |
82 |
Correct |
492 ms |
69748 KB |
Output is correct |
83 |
Correct |
456 ms |
50148 KB |
Output is correct |
84 |
Correct |
515 ms |
50780 KB |
Output is correct |
85 |
Correct |
451 ms |
50680 KB |
Output is correct |
86 |
Correct |
444 ms |
52448 KB |
Output is correct |
87 |
Correct |
463 ms |
52544 KB |
Output is correct |