#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MXN = 2e5 + 20 , LOG = 20;
vector<int> adj[MXN];
int h[MXN] , sz[MXN] , sttime[MXN] , p[LOG][MXN] , zaman;
int from[MXN] , to[MXN] , c[MXN];
ll dp[MXN] , pd[MXN];
vector<int> d[MXN];
int n,m;
struct fenwick {
int size;
vector<int> bit;
fenwick() {
size = 0;
}
void init(int n) {
size = n;
bit.assign(size , 0);
}
void add(int i , int k) {
for(; i < size ; i |= (i+1)) {
bit[i] += k;
}
}
void add(int l , int r , int k) {
add(l , k); add(r , -k);
}
int operator[](int i) {
int res = 0;
for(; i >= 0 ; i = (i&(i+1))-1) {
res += bit[i];
}
return res;
}
} f;
void prep(int v , int dad) {
p[0][v] = (dad == -1 ? v : dad);
h[v] = (dad == -1 ? 0 : h[dad]+1);
sz[v] = 1;
sttime[v] = zaman++;
for(auto u : adj[v]) {
if(u == dad) continue;
prep(u , v);
sz[v] += sz[u];
}
}
int kth_anc(int v , int k) {
while(k > 0) {
int x = __builtin_ctz(k);
v = p[x][v];
k -= (1 << x);
}
return v;
}
int LCA(int v , int u) {
if(h[v] > h[u]) swap(v , u);
u = kth_anc(u , h[u]-h[v]);
if(v == u) return v;
for(int i = LOG-1 ; i >= 0 ; i--) {
if(p[i][v] != p[i][u]) {
v = p[i][v]; u = p[i][u];
}
}
return p[0][v];
}
void DFS(int v , int dad) {
for(auto u : adj[v]) {
if(u == dad) continue;
DFS(u , v); pd[v] += dp[u];
}
dp[v] = pd[v];
for(auto p : d[v]) {
if(from[p] == v) {
dp[v] = max(dp[v] , c[p] + pd[v] + f[sttime[to[p]]]-f[sttime[v]]);
} else if(to[p] == v) {
dp[v] = max(dp[v] , c[p] + pd[v] + f[sttime[v]]-f[sttime[from[p]]]);
} else {
dp[v] = max(dp[v] , c[p] + pd[v] + f[sttime[from[p]]]-f[sttime[v]] + f[sttime[to[p]]]-f[sttime[v]]);
}
}
f.add(sttime[v] , sttime[v]+sz[v] , pd[v]-dp[v]);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cin >> n;
for(int i = 1 ; i < n ; i++) {
int v,u; cin >> v >> u;
adj[v].push_back(u); adj[u].push_back(v);
}
prep(1 , -1);
for(int i = 1 ; i < LOG ; i++) {
for(int j = 1 ; j <= n ; j++) {
p[i][j] = p[i-1][p[i-1][j]];
}
}
cin >> m;
for(int i = 0 ; i < m ; i++) {
cin >> from[i] >> to[i] >> c[i];
d[LCA(from[i] , to[i])].push_back(i);
}
f.init(n);
DFS(1 , -1);
cout << dp[1] << "\n";
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9804 KB |
Output is correct |
2 |
Correct |
5 ms |
9804 KB |
Output is correct |
3 |
Incorrect |
5 ms |
9804 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9804 KB |
Output is correct |
2 |
Incorrect |
5 ms |
9840 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9804 KB |
Output is correct |
2 |
Incorrect |
5 ms |
9840 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
131 ms |
27048 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9804 KB |
Output is correct |
2 |
Correct |
5 ms |
9804 KB |
Output is correct |
3 |
Incorrect |
5 ms |
9804 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9804 KB |
Output is correct |
2 |
Correct |
5 ms |
9804 KB |
Output is correct |
3 |
Incorrect |
5 ms |
9804 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |