#include <bits/stdc++.h>
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
using namespace std;
const int man = (int)(2e5 + 500);
int n, ans, timer;
int sz[man], tin[man], tout[man];
vector <int> g[man];
void dfs(int v, int pr) {
tin[v] = timer++;
sz[v] = 1;
for (int& u : g[v]) {
if (u == pr) {
continue;
}
dfs(u, v);
sz[v] += sz[u];
}
tout[v] = timer++;
}
bool upper(int v, int u) {
return (tin[v] <= tin[u]) && (tout[v] >= tout[u]);
}
void upd(int v, int u, int fx, int f1) {
int f2, f3;
if (upper(u, fx) == true) {
f2 = sz[u] - sz[fx];
f3 = n - sz[u];
} else {
f2 = sz[u];
f3 = n - sz[u] - sz[fx];
}
if (ans == -1) {
ans = max(max(f1, f2), f3) - min(min(f1, f2), f3);
} else {
ans = min(ans, max(max(f1, f2), f3) - min(min(f1, f2), f3));
}
}
void rec(int v, int pr, int mk, int cur) {
for (auto& u : g[v]) {
if ((u == pr) || (u == mk)) {
continue;
}
rec(u, v, mk, cur);
upd(v, u, mk, cur);
}
}
void calc(int v, int pr) {
for (auto& u : g[v]) {
if (u == pr) {
continue;
}
rec(0, -1, u, sz[u]);
calc(u, v);
}
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifdef _LOCAL
in("inD.txt");
out("outD.txt");
#endif
cin >> n;
for (int i = 1; i < n; ++i) {
int v, u;
cin >> v >> u;
--v, --u;
g[v].push_back(u);
g[u].push_back(v);
}
dfs(0, -1);
ans = -1;
calc(0, -1);
cout << ans << "\n";
return 0;
}
# |
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 |
5 ms |
5100 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 |
5 ms |
5100 KB |
Output is correct |
5 |
Correct |
4 ms |
5100 KB |
Output is correct |
6 |
Correct |
103 ms |
5100 KB |
Output is correct |
7 |
Correct |
104 ms |
5100 KB |
Output is correct |
8 |
Correct |
74 ms |
5228 KB |
Output is correct |
9 |
Correct |
85 ms |
5228 KB |
Output is correct |
10 |
Correct |
109 ms |
5224 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 |
5 ms |
5100 KB |
Output is correct |
5 |
Correct |
4 ms |
5100 KB |
Output is correct |
6 |
Correct |
103 ms |
5100 KB |
Output is correct |
7 |
Correct |
104 ms |
5100 KB |
Output is correct |
8 |
Correct |
74 ms |
5228 KB |
Output is correct |
9 |
Correct |
85 ms |
5228 KB |
Output is correct |
10 |
Correct |
109 ms |
5224 KB |
Output is correct |
11 |
Execution timed out |
1068 ms |
14572 KB |
Time limit exceeded |
12 |
Halted |
0 ms |
0 KB |
- |