/**
* author: wxhtzdy
* created: 08.08.2022 14:06:23
**/
#include <bits/stdc++.h>
using namespace std;
template <typename T>
class fenwick {
public:
vector<T> fenw;
int n;
fenwick(int _n) : n(_n) {
fenw.resize(n);
}
void modify(int x, T v) {
while (x < n) {
fenw[x] += v;
x |= (x + 1);
}
}
T get(int x) {
T v{};
while (x >= 0) {
v += fenw[x];
x = (x & (x + 1)) - 1;
}
return v;
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> c(n);
for (int i = 0; i < n; i++) {
cin >> c[i];
}
auto xs = c;
sort(xs.begin(), xs.end());
xs.erase(unique(xs.begin(), xs.end()), xs.end());
for (int i = 0; i < n; i++) {
c[i] = lower_bound(xs.begin(), xs.end(), c[i]) - xs.begin();
}
vector<vector<int>> g(n);
vector<pair<int, int>> edges;
for (int i = 0; i < n - 1; i++) {
int u, v;
cin >> u >> v;
--u; --v;
g[u].push_back(v);
g[v].push_back(u);
edges.emplace_back(u, v);
}
vector<int> par(n);
vector<int> dep(n);
vector<int> tin(n);
vector<int> tout(n);
int T = 0;
function<void(int, int)> Dfs = [&](int v, int pr) {
tin[v] = ++T;
par[v] = pr;
dep[v] = dep[pr] + 1;
for (int u : g[v]) {
if (u != pr) {
Dfs(u, v);
}
}
tout[v] = T;
};
Dfs(0, 0);
const int L = 25;
vector<vector<int>> jump(n, vector<int>(L));
for (int i = 0; i < n; i++) {
jump[i][0] = par[i];
}
for (int j = 1; j < L; j++) {
for (int i = 0; i < n; i++) {
jump[i][j] = jump[jump[i][j - 1]][j - 1];
}
}
auto isPar = [&](int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
};
auto Find = [&](int u, int v) {
for (int i = L - 1; i >= 0; i--) {
if (!isPar(jump[v][i], u)) {
v = jump[v][i];
}
}
return v;
};
vector<int> f(n, 0);
f[0] = 0;
fenwick<int> fenw(n);
for (auto& p : edges) {
int a = p.first;
int b = p.second;
int x = 0;
vector<pair<int, int>> v;
while (x != b && !isPar(f[x], b)) {
int i = Find(b, f[x]);
int j = Find(f[x], b);
f[j] = f[x];
v.emplace_back(dep[i] - dep[x], c[f[x]]);
x = i;
}
if (x != b) {
v.emplace_back(dep[b] - dep[x], c[f[x]]);
}
f[0] = b;
long long ans = 0;
reverse(v.begin(), v.end());
for (auto& p : v) {
ans += fenw.get(p.second - 1) * 1LL * p.first;
fenw.modify(p.second, p.first);
}
cout << ans << '\n';
for (auto& p : v) {
fenw.modify(p.second, -p.first);
}
}
return 0;
}
Compilation message
construction.cpp: In function 'int main()':
construction.cpp:100:9: warning: unused variable 'a' [-Wunused-variable]
100 | int a = p.first;
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Execution timed out |
2079 ms |
66152 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Execution timed out |
2079 ms |
66152 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Execution timed out |
2079 ms |
66152 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
