#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-Ofast")
#define N 200500
#define NN 205000
#define PB push_back
#define endl '\n'
#define pri(x) cout << x << endl
#define _ << " " <<
#define all(x) x.begin(), x.end()
#define sz(x) int(x.size())
#define M ll(1e9 + 7)
#define F first
#define S second
using namespace std;
//using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef short int si;
typedef unsigned long long ull;
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
vector <int> g[N];
int ans = 1e9, siz[N], n;
multiset <int> str;
set <int> st;
void rec(int v, int p)
{
siz[v] = 1;
for (auto it : g[v])
{
if (it == p) continue;
rec(it, v);
siz[v] += siz[it];
}
}
void dfs(int v, int p)
{
int val = (n + siz[v]) / 2;
int kol = 200;
if (sz(str))
{
auto it = str.lower_bound(val);
if (it == str.end()) it--;
while (kol && sz(str))
{
int vt = (*it);
int a1 = n - vt, a2 = vt - siz[v], a3 = siz[v];
ans = min(ans, max(a1, max(a2, a3)) - min(a1, min(a2, a3)));
kol--;
if (it == str.begin())
break;
it--;
}
}
kol = 200;
if (sz(str))
{
auto it = str.lower_bound(val);
if (it == str.end()) it--;
while (kol && sz(str))
{
int vt = (*it);
int a1 = n - vt, a2 = vt - siz[v], a3 = siz[v];
ans = min(ans, max(a1, max(a2, a3)) - min(a1, min(a2, a3)));
kol--;
it++;
if (it == str.end())
break;
}
}
if (sz(st))
{
int kol = 200;
auto itr = st.lower_bound(val);
if (itr == st.end()) itr--;
while (kol && sz(st))
{
int vt = (*itr);
int a1 = n - siz[v] - vt, a2 = siz[v], a3 = vt;
int val = max(a1, max(a2, a3)) - min(a1, min(a2, a3));
ans = min(ans, val);
kol--;
if (itr == st.begin())
break;
itr--;
}
kol = 200;
itr = st.lower_bound(val);
while (kol)
{
int vt = (*itr);
int a1 = n - siz[v] - vt, a2 = siz[v], a3 = vt;
int val = max(a1, max(a2, a3)) - min(a1, min(a2, a3));
ans = min(ans, val);
kol--;
itr++;
if (itr == st.end())
break;
}
}
str.insert(siz[v]);
for (auto it : g[v])
{
if (it == p) continue;
dfs(it, v);
}
str.erase(str.find(siz[v]));
st.insert(siz[v]);
}
int main()
{
ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// freopen("1.in", "r", stdin);
cin >> n;
for (int i = 1; i < n; i++)
{
int x, y;
cin >> x >> y;
g[x].PB(y);
g[y].PB(x);
}
rec(1, -1);
dfs(1, -1);
pri(ans);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
5100 KB |
Output is correct |
2 |
Correct |
4 ms |
5100 KB |
Output is correct |
3 |
Correct |
4 ms |
5100 KB |
Output is correct |
4 |
Correct |
4 ms |
5120 KB |
Output is correct |
5 |
Correct |
4 ms |
5100 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
5100 KB |
Output is correct |
2 |
Correct |
4 ms |
5100 KB |
Output is correct |
3 |
Correct |
4 ms |
5100 KB |
Output is correct |
4 |
Correct |
4 ms |
5120 KB |
Output is correct |
5 |
Correct |
4 ms |
5100 KB |
Output is correct |
6 |
Correct |
5 ms |
5100 KB |
Output is correct |
7 |
Correct |
7 ms |
5100 KB |
Output is correct |
8 |
Correct |
6 ms |
5100 KB |
Output is correct |
9 |
Correct |
7 ms |
5100 KB |
Output is correct |
10 |
Correct |
6 ms |
5100 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
5100 KB |
Output is correct |
2 |
Correct |
4 ms |
5100 KB |
Output is correct |
3 |
Correct |
4 ms |
5100 KB |
Output is correct |
4 |
Correct |
4 ms |
5120 KB |
Output is correct |
5 |
Correct |
4 ms |
5100 KB |
Output is correct |
6 |
Correct |
5 ms |
5100 KB |
Output is correct |
7 |
Correct |
7 ms |
5100 KB |
Output is correct |
8 |
Correct |
6 ms |
5100 KB |
Output is correct |
9 |
Correct |
7 ms |
5100 KB |
Output is correct |
10 |
Correct |
6 ms |
5100 KB |
Output is correct |
11 |
Correct |
537 ms |
12396 KB |
Output is correct |
12 |
Correct |
752 ms |
12248 KB |
Output is correct |
13 |
Correct |
449 ms |
13036 KB |
Output is correct |
14 |
Correct |
494 ms |
12656 KB |
Output is correct |
15 |
Correct |
640 ms |
12380 KB |
Output is correct |
16 |
Correct |
155 ms |
12904 KB |
Output is correct |
17 |
Correct |
529 ms |
12396 KB |
Output is correct |
18 |
Execution timed out |
1048 ms |
21228 KB |
Time limit exceeded |
19 |
Halted |
0 ms |
0 KB |
- |