#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
vector <int> g[N];
int a[N], dp[N], pref[N];
long long f[25][2], ans = 0;
bool visited[N];
void dfs (int u, int p) {
dp[u] = 1;
for (auto v: g[u]) {
if (visited[v] || v == p) continue;
dfs(v, u);
dp[u] += dp[v];
}
}
int find_centroid (int u, int p, int sz) {
for (auto v: g[u]) {
if (v != p && !visited[v] && dp[v] > sz/2) return find_centroid(v, u, sz);
}
return u;
}
void redfs (int u, int p) {
ans += pref[u];
for (int i = 0; i < 25; i++) ans = ans + (1LL << i) * f[i][(pref[u] >> i & 1LL) ^ 1LL];
for (auto v: g[u]) {
if (visited[v] || v == p) continue;
pref[v] = pref[u] ^ a[v];
redfs(v, u);
}
}
void redfs_2 (int u, int p, int val) {
for (int i = 0; i < 25; i++) f[i][pref[u] >> i & 1LL] += val;
for (auto v: g[u]) {
if (visited[v] || v == p) continue;
pref[v] = pref[u] ^ a[v];
redfs_2(v, u, val);
}
}
void centroid (int root) {
dfs(root, root);
int cen = find_centroid(root, root, dp[root]);
visited[cen] = true;
for (auto v: g[cen]) {
if (visited[v]) continue;
pref[v] = a[cen] ^ a[v];
redfs(v, cen);
pref[v] = a[v];
redfs_2(v, cen, 1);
}
for (auto v: g[cen]) {
if (visited[v]) continue;
pref[v] = a[v];
redfs_2(v, cen, -1);
}
for (auto v: g[cen]) {
if (!visited[v]) centroid(v);
}
}
int main(){
int n;
scanf("%d", &n);
for (int i = 1; i <= n; i++) scanf("%d", &a[i]), ans += a[i];
for (int i = 1; i <= n - 1; i++) {
int u, v;
scanf("%d %d", &u, &v);
g[u].push_back(v);
g[v].push_back(u);
}
centroid(1);
printf("%lld", ans);
return 0;
}
Compilation message
deblo.cpp: In function 'int main()':
deblo.cpp:77:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
deblo.cpp:78:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
for (int i = 1; i <= n; i++) scanf("%d", &a[i]), ans += a[i];
~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
deblo.cpp:81:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &u, &v);
~~~~~^~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
2680 KB |
Output is correct |
2 |
Correct |
4 ms |
2804 KB |
Output is correct |
3 |
Correct |
4 ms |
2804 KB |
Output is correct |
4 |
Correct |
9 ms |
2804 KB |
Output is correct |
5 |
Correct |
7 ms |
2804 KB |
Output is correct |
6 |
Correct |
307 ms |
15476 KB |
Output is correct |
7 |
Correct |
298 ms |
17008 KB |
Output is correct |
8 |
Correct |
324 ms |
17008 KB |
Output is correct |
9 |
Correct |
310 ms |
17008 KB |
Output is correct |
10 |
Correct |
356 ms |
17008 KB |
Output is correct |