#include <iostream>
#include <algorithm>
#include <cstring>
#include <string.h>
#include <vector>
#include <math.h>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <numeric>
#include <random>
#include <chrono>
#include <fstream>
#include <stack>
#include <cmath>
#define bit(x, i) (((x) >> (i)) & 1LL)
#define rand rd
#define PI acos(-1)
using namespace std;
typedef long long int ll;
const int maxn = 2e5 + 5;
const ll mod = 1e9 + 7;
const int inf = 1e9;
const ll base = 1e5 + 7;
using pll = pair<ll, ll>;
const string NAME = "LOCO";
const int NTEST = 100;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {
return l + rd() % (r - l + 1);
}
int n, cnt = 0;
vector<int> adj[maxn];
int sz[maxn], tin[maxn], tout[maxn];
set<int> is_anc, is_not_anc;
void dfs_sz(int u, int p) {
tin[u] = ++cnt;
sz[u] = 1;
for (auto j : adj[u]) {
if (j == p)
continue;
dfs_sz(j, u);
sz[u] += sz[j];
}
tout[u] = cnt;
}
vector<int> find_pos(set<int> &s, int val) {
vector<int> res;
auto it = s.upper_bound(val);
if (it != s.end())
res.push_back(*it);
if (it != s.begin()) {
--it;
res.push_back(*it);
}
return res;
}
int calc(int a, int b, int c) {
return max({a, b, c}) - min({a, b, c});
}
int go(int u, int p) {
is_anc.insert(sz[u]);
int res = inf;
for (auto j : find_pos(is_anc, (n + sz[u]) / 2)) {
res = min(res, calc(sz[u], j - sz[u], n - j));
}
for (auto j : find_pos(is_not_anc, (n - sz[u]) / 2)) {
res = min(res, calc(sz[u], j, n - j - sz[u]));
}
for (auto j : adj[u]) {
if (j == p)
continue;
res = min(go(j, u), res);
}
is_anc.erase(sz[u]);
is_not_anc.insert(sz[u]);
return res;
}
int main() {
// #ifndef ONLINE_JUDGE
// freopen("TASK.inp", "r", stdin);
// freopen("TASK.out", "w", stdout);
// #endif // ONLINE_JUDGE
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
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);
}
dfs_sz(1, 1);
cout << go(1, 1);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
7252 KB |
Output is correct |
2 |
Correct |
2 ms |
7252 KB |
Output is correct |
3 |
Correct |
2 ms |
7252 KB |
Output is correct |
4 |
Correct |
2 ms |
7336 KB |
Output is correct |
5 |
Correct |
2 ms |
7252 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
7252 KB |
Output is correct |
2 |
Correct |
2 ms |
7252 KB |
Output is correct |
3 |
Correct |
2 ms |
7252 KB |
Output is correct |
4 |
Correct |
2 ms |
7336 KB |
Output is correct |
5 |
Correct |
2 ms |
7252 KB |
Output is correct |
6 |
Correct |
2 ms |
7252 KB |
Output is correct |
7 |
Correct |
3 ms |
7252 KB |
Output is correct |
8 |
Correct |
3 ms |
7252 KB |
Output is correct |
9 |
Correct |
3 ms |
7252 KB |
Output is correct |
10 |
Correct |
2 ms |
7252 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
7252 KB |
Output is correct |
2 |
Correct |
2 ms |
7252 KB |
Output is correct |
3 |
Correct |
2 ms |
7252 KB |
Output is correct |
4 |
Correct |
2 ms |
7336 KB |
Output is correct |
5 |
Correct |
2 ms |
7252 KB |
Output is correct |
6 |
Correct |
2 ms |
7252 KB |
Output is correct |
7 |
Correct |
3 ms |
7252 KB |
Output is correct |
8 |
Correct |
3 ms |
7252 KB |
Output is correct |
9 |
Correct |
3 ms |
7252 KB |
Output is correct |
10 |
Correct |
2 ms |
7252 KB |
Output is correct |
11 |
Correct |
82 ms |
16204 KB |
Output is correct |
12 |
Correct |
103 ms |
16352 KB |
Output is correct |
13 |
Correct |
79 ms |
16800 KB |
Output is correct |
14 |
Correct |
85 ms |
16584 KB |
Output is correct |
15 |
Correct |
91 ms |
16216 KB |
Output is correct |
16 |
Correct |
62 ms |
16072 KB |
Output is correct |
17 |
Correct |
96 ms |
16480 KB |
Output is correct |
18 |
Correct |
128 ms |
24908 KB |
Output is correct |
19 |
Correct |
83 ms |
16460 KB |
Output is correct |
20 |
Correct |
122 ms |
16460 KB |
Output is correct |