#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 5e5 + 10;
const int LOGN = 20;
vector<pair<int, int>> g[maxn];
ll best[maxn];
int sz[maxn], pi[maxn];
bool block[maxn];
int n;
int st[maxn], fin[maxn], timer = 0;
int up[maxn][LOGN];
ll h[maxn];
void dfs(int v, int p) {
st[v] = timer++;
up[v][0] = p;
for(int i = 1; i < LOGN; i++)
up[v][i] = up[up[v][i-1]][i-1];
for(auto [to, d] : g[v]) if(to != p) {
h[to] = h[v] + d;
dfs(to, v);
}
fin[v] = timer++;
}
bool is_parent(int u, int v) { return st[u] <= st[v] and fin[v] <= fin[u]; }
int lca(int u, int v) {
if(is_parent(u, v)) return u;
if(is_parent(v, u)) return v;
for(int i = LOGN-1; i >= 0; i--) {
if(!is_parent(up[u][i], v)) {
u = up[u][i];
}
}
return up[u][0];
}
ll dist(int u, int v) {
int p = lca(u, v);
return h[u] + h[v] - 2 * h[p];
}
int centroid(int v, int p, int n) {
sz[v] = 1;
int mx=0, cen=0;
for (auto [u, d] : g[v]) if (u!=p && !block[u]) {
cen ^= centroid(u, v, n);
sz[v] += sz[u], mx=max(mx, sz[u]);
}
mx = max(mx, n-sz[v]);
if (2*mx <= n) pi[cen=v]=p;
return cen;
}
void decompose(int x, int p=-1, int m=n) {
int cen = centroid(x, -1, m);
if (~pi[cen]) sz[pi[cen]]=m-sz[cen];
pi[cen]=p; block[cen]=1;
for (auto [v, d] : g[cen]) if (!block[v]) {
decompose(v, cen, sz[v]);
}
}
const ll INF = (ll) 2e18;
void update(int v) {
best[v] = 0;
int u = v;
while(pi[u] != -1) {
u = pi[u];
best[u] = min(best[u], dist(v, u));
}
}
void clean(int v) {
do {
best[v] = INF;
v = pi[v];
}while(v != -1);
}
ll query(int v) {
ll ans = best[v];
int u = v;
while(pi[u] != -1) {
u = pi[u];
ans = min(ans, best[u] + dist(u, v));
}
return ans;
}
void Init(int N, int a[], int b[], int d[]) {
n = N;
for(int i = 0; i < n-1; i++) {
int u = a[i], v = b[i];
g[u].push_back({v, d[i]});
g[v].push_back({u, d[i]});
}
for(int i = 0; i < n; i++) best[i] = INF;
decompose(0);
dfs(0, 0);
}
ll Query(int s, int x[], int t, int y[]) {
for(int i = 0; i < s; i++) update(x[i]);
ll ans = INF;
for(int j = 0; j < t; j++) ans = min(ans, query(y[j]));
for(int i = 0; i < s; i++) clean(x[i]);
return ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
41308 KB |
Output is correct |
2 |
Correct |
441 ms |
57432 KB |
Output is correct |
3 |
Correct |
920 ms |
57440 KB |
Output is correct |
4 |
Correct |
924 ms |
57424 KB |
Output is correct |
5 |
Correct |
456 ms |
57680 KB |
Output is correct |
6 |
Correct |
150 ms |
57316 KB |
Output is correct |
7 |
Correct |
904 ms |
57428 KB |
Output is correct |
8 |
Correct |
968 ms |
57384 KB |
Output is correct |
9 |
Correct |
446 ms |
57820 KB |
Output is correct |
10 |
Correct |
149 ms |
57172 KB |
Output is correct |
11 |
Correct |
908 ms |
57388 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
41304 KB |
Output is correct |
2 |
Correct |
1535 ms |
128196 KB |
Output is correct |
3 |
Correct |
3100 ms |
131200 KB |
Output is correct |
4 |
Correct |
469 ms |
128376 KB |
Output is correct |
5 |
Correct |
1987 ms |
159008 KB |
Output is correct |
6 |
Correct |
3108 ms |
131904 KB |
Output is correct |
7 |
Correct |
2178 ms |
77132 KB |
Output is correct |
8 |
Correct |
229 ms |
76992 KB |
Output is correct |
9 |
Correct |
945 ms |
80536 KB |
Output is correct |
10 |
Correct |
2161 ms |
77904 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
41308 KB |
Output is correct |
2 |
Correct |
441 ms |
57432 KB |
Output is correct |
3 |
Correct |
920 ms |
57440 KB |
Output is correct |
4 |
Correct |
924 ms |
57424 KB |
Output is correct |
5 |
Correct |
456 ms |
57680 KB |
Output is correct |
6 |
Correct |
150 ms |
57316 KB |
Output is correct |
7 |
Correct |
904 ms |
57428 KB |
Output is correct |
8 |
Correct |
968 ms |
57384 KB |
Output is correct |
9 |
Correct |
446 ms |
57820 KB |
Output is correct |
10 |
Correct |
149 ms |
57172 KB |
Output is correct |
11 |
Correct |
908 ms |
57388 KB |
Output is correct |
12 |
Correct |
7 ms |
41304 KB |
Output is correct |
13 |
Correct |
1535 ms |
128196 KB |
Output is correct |
14 |
Correct |
3100 ms |
131200 KB |
Output is correct |
15 |
Correct |
469 ms |
128376 KB |
Output is correct |
16 |
Correct |
1987 ms |
159008 KB |
Output is correct |
17 |
Correct |
3108 ms |
131904 KB |
Output is correct |
18 |
Correct |
2178 ms |
77132 KB |
Output is correct |
19 |
Correct |
229 ms |
76992 KB |
Output is correct |
20 |
Correct |
945 ms |
80536 KB |
Output is correct |
21 |
Correct |
2161 ms |
77904 KB |
Output is correct |
22 |
Correct |
1937 ms |
132740 KB |
Output is correct |
23 |
Correct |
2106 ms |
134296 KB |
Output is correct |
24 |
Correct |
5005 ms |
135772 KB |
Output is correct |
25 |
Correct |
4726 ms |
138116 KB |
Output is correct |
26 |
Correct |
4674 ms |
136244 KB |
Output is correct |
27 |
Correct |
2469 ms |
157696 KB |
Output is correct |
28 |
Correct |
521 ms |
134840 KB |
Output is correct |
29 |
Correct |
4816 ms |
135824 KB |
Output is correct |
30 |
Correct |
4869 ms |
135192 KB |
Output is correct |
31 |
Correct |
5351 ms |
135724 KB |
Output is correct |
32 |
Correct |
939 ms |
81292 KB |
Output is correct |
33 |
Correct |
225 ms |
76996 KB |
Output is correct |
34 |
Correct |
889 ms |
75600 KB |
Output is correct |
35 |
Correct |
932 ms |
75824 KB |
Output is correct |
36 |
Correct |
2176 ms |
76352 KB |
Output is correct |
37 |
Correct |
2227 ms |
76192 KB |
Output is correct |