#include <bits/stdc++.h>
//ako ovaj vaso daso misli da me pobedjuje.....
using namespace std;
#define int long long
#define f first
#define s second
const int N = 2e5 + 69;
const int K = 18;
int up[N][K], tin[N], tout[N], timer, dep[N];
int st[4 * N], act[4 * N];
int n, a[N], vis[N], bst[N];
vector<int> g[N];
void modify(int v, int tl, int tr, int p, int x) {
if (tl == tr) {
st[v] = x;
}
else {
int mid = (tl + tr) / 2;
if (p <= mid)
modify(v * 2, tl, mid, p, x);
else
modify(v * 2 + 1, mid + 1, tr, p, x);
if (a[st[v * 2]] > a[st[v * 2 + 1]])
st[v] = st[v * 2];
else
st[v] = st[v * 2 + 1];
}
}
int get(int v, int tl, int tr, int l, int r) {
if (tl > r || tr < l || act[v])
return 0;
else if (tl >= l && tr <= r)
return st[v];
else {
int mid = (tl + tr) / 2;
int left = get(v * 2, tl, mid, l, r);
int right = get(v * 2 + 1, mid + 1, tr, l, r);
if (a[left] > a[right])
return left;
return right;
}
}
bool anc(int u, int v) {
return tin[u] <= tin[v] && tout[u] >= tout[v];
}
void dfs(int v, int p) {
up[v][0] = p;
tin[v] = ++timer;
dep[v] = dep[p] + 1;
for (int i = 1;i < K;i++)
up[v][i] = up[up[v][i - 1]][i - 1];
bst[v] = v;
for (auto u : g[v]) {
if (u == p)
continue;
dfs(u, v);
if (a[bst[u]] > a[bst[v]])
bst[v] = bst[u];
}
tout[v] = timer;
}
int Lca(int a, int b) {
if (anc(a, b))
return a;
else if (anc(b, a))
return b;
for (int i = K - 1;i >= 0;i--) {
if (!anc(up[a][i], b) && up[a][i] > 0)
a = up[a][i];
}
return up[a][0];
}
int distance(int a, int b) {
if (a == 0 || b == 0)
return 0;
int lc = Lca(a, b);
return dep[a] + dep[b] - 2 * dep[lc];
}
pair<int, int> find_mx(int v, int p) {
if (vis[v])
return {0, 0};
int mx = a[v], s = v;
for (auto u : g[v]) {
if (u == p)
continue;
auto x = find_mx(u, v);
if (x.f > mx) {
mx = x.f;
s = x.s;
}
}
return {mx, s};
}
void activate(int v, int tl, int tr, int l, int r, int x) {
if (tl > r || tr < l)
return;
else if (tl >= l && tr <= r)
act[v] = x;
else {
int mid = (tl + tr) / 2;
activate(v * 2, tl, mid, l, r, x);
activate(v * 2 + 1, mid + 1, tr, l, r, x);
if (act[v * 2] == 1 && act[v * 2 + 1] == 1)
st[v] = 0;
else if (act[v * 2] == 1 && act[v * 2 + 1] == 0)
st[v] = st[v * 2 + 1];
else if (act[v * 2] == 0 && act[v * 2 + 1] == 1) {
st[v] = st[v * 2];
}
else {
if (a[st[v * 2]] > a[st[v * 2 + 1]])
st[v] = st[v * 2];
else
st[v] = st[v * 2 + 1];
}
}
}
int solve(int x, int p) {
int v = get(1, 1, n, tin[x], tout[x]);
vis[v] = 1;
int res = 0;
for (auto u : g[v]) {
if (vis[u])
continue;
if (dep[u] > dep[v])
res = max(res, solve(u, v));
else {
activate(1, 1, n, tin[v], tout[v], 1);
res = max(res, solve(x, v));
activate(1, 1, n, tin[v], tout[v], 0);
}
}
return res + distance(v, p);
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int tt = 1;
//cin >> tt;
while (tt--) {
cin >> n;
for (int i = 1;i <= n;i++)
cin >> a[i];
for (int i = 1;i <= n - 1;i++) {
int a, b;
cin >> a >> b;
g[a].push_back(b);
g[b].push_back(a);
}
dfs(1, 0);
for (int i = 1;i <= n;i++)
modify(1, 1, n, tin[i], i);
cout << solve(1, 0) << '\n';
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
2 ms |
14940 KB |
Output is correct |
3 |
Correct |
3 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
14940 KB |
Output is correct |
5 |
Correct |
3 ms |
14940 KB |
Output is correct |
6 |
Correct |
3 ms |
14940 KB |
Output is correct |
7 |
Correct |
3 ms |
14940 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
15360 KB |
Output is correct |
10 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |