#include <bits/stdc++.h>
using namespace std;
const int kN = 1e4;
const int kK = 100;
int a[1 + kN];
vector<int> g[1 + kN], st[1 + kK], dr[1 + kK];
vector<pair<int, int>> intervals[1 + kN];
bitset<1 + kK + 1> reach;
void dfs(int u) {
for (const int &v : g[u]) {
dfs(v);
}
for (int i = 1; i <= kK; ++i) {
st[i].clear();
dr[i].clear();
}
for (const int &v : g[u]) {
for (const auto &range : intervals[v]) {
if (a[u] < range.first) {
dr[range.second].emplace_back(range.first - 1);
} else if (range.second < a[u]) {
st[range.first].emplace_back(range.second + 1);
}
}
intervals[v].clear();
}
reach.reset();
reach.set(a[u]);
vector<int> left;
for (int l = kK; l > 0; --l) {
if (!reach[l]) {
for (const int &r : st[l]) {
if (reach[r]) {
reach.set(l);
break;
}
}
}
if (reach[l]) {
left.emplace_back(l);
}
}
reach.reset();
reach.set(a[u]);
vector<int> right;
for (int r = 1; r <= kK; ++r) {
if (!reach[r]) {
for (const int &l : dr[r]) {
if (reach[l]) {
reach.set(r);
break;
}
}
}
if (reach[r]) {
right.emplace_back(r);
}
}
for (const int &l : left) {
for (const int &r : right) {
intervals[u].emplace_back(l, r);
}
}
left.clear();
right.clear();
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
}
for (int i = 1; i < n; ++i) {
int u, v;
cin >> u >> v;
g[u].emplace_back(v);
}
dfs(1);
cout << intervals[1].size() << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
724 KB |
Output is correct |
2 |
Correct |
1 ms |
724 KB |
Output is correct |
3 |
Correct |
1 ms |
796 KB |
Output is correct |
4 |
Correct |
1 ms |
724 KB |
Output is correct |
5 |
Correct |
1 ms |
724 KB |
Output is correct |
6 |
Correct |
1 ms |
724 KB |
Output is correct |
7 |
Correct |
1 ms |
724 KB |
Output is correct |
8 |
Correct |
1 ms |
724 KB |
Output is correct |
9 |
Correct |
1 ms |
724 KB |
Output is correct |
10 |
Correct |
1 ms |
724 KB |
Output is correct |
11 |
Correct |
14 ms |
1336 KB |
Output is correct |
12 |
Correct |
12 ms |
1364 KB |
Output is correct |
13 |
Correct |
13 ms |
1440 KB |
Output is correct |
14 |
Correct |
24 ms |
8528 KB |
Output is correct |
15 |
Correct |
24 ms |
8620 KB |
Output is correct |
16 |
Correct |
23 ms |
8568 KB |
Output is correct |
17 |
Correct |
14 ms |
1360 KB |
Output is correct |
18 |
Correct |
13 ms |
1400 KB |
Output is correct |
19 |
Correct |
13 ms |
3680 KB |
Output is correct |
20 |
Correct |
13 ms |
3668 KB |
Output is correct |