//author:
#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define ONLINE_JUDGE
const int MAXN = 2000 + 5;
bool ok[MAXN][MAXN];
void solve() {
memset(ok, true, sizeof(ok));
int n;
cin >> n;
vector <int> adj[n +1];
vector <pair <int, int>> edges(n);
for(int i = 1; i <= n -1; i++) {
cin >> edges[i].first >> edges[i].second;
if(edges[i].first > edges[i].second) {
swap(edges[i].first, edges[i].second);
}
adj[edges[i].first].emplace_back(edges[i].second);
adj[edges[i].second].emplace_back(edges[i].first);
}
function <int(int, int)> dfs = [&](int node, int par) -> int {
//cerr << node << " " << par << "\n";
int res = 1;
for(int &child : adj[node]) {
if(child != par && ok[child][node]) {
res += dfs(child, node);
}
}
return res;
};
int ans = n;
for(int i = 1; i <= n -1; i++) {
for(int j = i +1; j <= n -1; j++) {
auto &[a, b] = edges[i];
auto &[c, d] = edges[j];
ok[a][b] = ok[b][a] = false;
ok[c][d] = ok[d][c] = false;
vector <int> sizes;
sizes.emplace_back(dfs(a, 0));
sizes.emplace_back(dfs(b, 0));
sizes.emplace_back(dfs(c, 0));
sizes.emplace_back(dfs(d, 0));
sort(sizes.begin(), sizes.end());
sizes.erase(unique(sizes.begin(), sizes.end()), sizes.end());
if(sizes.size() == 1) {
sizes.emplace_back(sizes.front());
}
int sz1 = sizes[0];
int sz2 = sizes[1];
int sz3 = n - (sizes[0] + sizes[1]);
ok[a][b] = ok[b][a] = true;
ok[c][d] = ok[d][c] = true;
ans = min(ans, max({sz1, sz2, sz3}) - min({sz1, sz2, sz3}));
}
}
cout << ans;
return;
}
signed main() {
#ifndef ONLINE_JUDGE
freopen(".in", "r", stdin);
freopen(".out", "w", stdout);
#endif
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int t = 1; //cin >> t;
while(t--)
solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
54 ms |
4184 KB |
Output is correct |
2 |
Correct |
59 ms |
4188 KB |
Output is correct |
3 |
Correct |
55 ms |
4188 KB |
Output is correct |
4 |
Correct |
53 ms |
4184 KB |
Output is correct |
5 |
Correct |
55 ms |
4440 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
54 ms |
4184 KB |
Output is correct |
2 |
Correct |
59 ms |
4188 KB |
Output is correct |
3 |
Correct |
55 ms |
4188 KB |
Output is correct |
4 |
Correct |
53 ms |
4184 KB |
Output is correct |
5 |
Correct |
55 ms |
4440 KB |
Output is correct |
6 |
Execution timed out |
1039 ms |
4696 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
54 ms |
4184 KB |
Output is correct |
2 |
Correct |
59 ms |
4188 KB |
Output is correct |
3 |
Correct |
55 ms |
4188 KB |
Output is correct |
4 |
Correct |
53 ms |
4184 KB |
Output is correct |
5 |
Correct |
55 ms |
4440 KB |
Output is correct |
6 |
Execution timed out |
1039 ms |
4696 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |