#include "bits/stdc++.h"
using namespace std;
#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif
const int LOG = 18;
const int N = 1e5 + 5;
const long long INF = 1e15;
int dep[N];
bool shop[N];
int pr[LOG][N];
vector<int> g[N];
long long dis[N];
array<int, 3> e[N];
long long dp[LOG][N];
int cnt, in[N], out[N];
void dfs(int v, int p) {
in[v] = cnt++;
dp[0][v] = (shop[v] ? dis[v] : INF);
for (int i : g[v]) {
int u = v ^ e[i][0] ^ e[i][1];
if (u == p) continue;
dep[u] = dep[v] + 1;
dis[u] = dis[v] + e[i][2];
pr[0][u] = v;
for (int j = 1; j < LOG; ++j) {
pr[j][u] = pr[j - 1][pr[j - 1][u]];
}
dfs(u, v);
dp[0][v] = min(dp[0][v], dp[0][u]);
}
out[v] = cnt - 1;
}
void init_dp(int v, int p) {
for (int i : g[v]) {
int u = v ^ e[i][0] ^ e[i][1];
if (u == p) continue;
for (int j = 1; j < LOG; ++j) {
dp[j][u] = min(dp[j - 1][u], dp[j - 1][pr[j - 1][u]]);
}
init_dp(u, v);
}
}
bool isParent(int v, int u) {
return in[v] <= in[u] && out[v] >= out[u];
}
long long get(int u, int v) {
long long ret = INF;
long long cc = dis[u];
//deb(u) deb(v) deb(dp[0][v]) cout << '\n';
for (int j = 0; j < LOG; ++j) {
if ((dep[u] - dep[v]) >> j & 1) {
ret = min(ret, dp[j][u] + cc);
u = pr[j][u];
}
}
assert(u == v);
ret = min(ret, dp[0][u] + cc);
return ret;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, s, q, ep;
cin >> n >> s >> q >> ep;
for (int i = 0; i < n - 1; ++i) {
int u, v, w;
cin >> u >> v >> w;
e[i] = {u, v, w};
g[u].push_back(i);
g[v].push_back(i);
}
for (int i = 0; i < s; ++i) {
int v;
cin >> v;
shop[v] = true;
}
dfs(ep, ep);
for (int i = 1; i <= n; ++i) {
if (dp[0][i] != INF) {
dp[0][i] -= 2 * dis[i];
}
}
init_dp(ep, ep);
while (q--) {
int i, v;
cin >> i >> v;
--i;
int qu = e[i][0];
int qv = e[i][1];
if (dis[qv] > dis[qu]) {
swap(qv, qu);
}
if (isParent(qu, v)) {
long long ans = get(v, qu);
if (ans < INF) {
cout << ans << '\n';
} else {
cout << "oo" << '\n';
}
} else {
cout << "escaped" << '\n';
}
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
23128 KB |
Output is correct |
2 |
Correct |
5 ms |
23132 KB |
Output is correct |
3 |
Correct |
4 ms |
23016 KB |
Output is correct |
4 |
Correct |
6 ms |
23132 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
23128 KB |
Output is correct |
2 |
Correct |
5 ms |
23132 KB |
Output is correct |
3 |
Correct |
4 ms |
23016 KB |
Output is correct |
4 |
Correct |
6 ms |
23132 KB |
Output is correct |
5 |
Correct |
4 ms |
23132 KB |
Output is correct |
6 |
Correct |
4 ms |
23172 KB |
Output is correct |
7 |
Correct |
3 ms |
23132 KB |
Output is correct |
8 |
Correct |
3 ms |
23132 KB |
Output is correct |
9 |
Correct |
3 ms |
23132 KB |
Output is correct |
10 |
Correct |
4 ms |
23132 KB |
Output is correct |
11 |
Correct |
3 ms |
23132 KB |
Output is correct |
12 |
Correct |
3 ms |
23132 KB |
Output is correct |
13 |
Correct |
3 ms |
23128 KB |
Output is correct |
14 |
Correct |
4 ms |
23388 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
109 ms |
34908 KB |
Output is correct |
2 |
Correct |
119 ms |
34640 KB |
Output is correct |
3 |
Correct |
141 ms |
34640 KB |
Output is correct |
4 |
Correct |
149 ms |
36688 KB |
Output is correct |
5 |
Correct |
127 ms |
36432 KB |
Output is correct |
6 |
Correct |
150 ms |
38500 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
23128 KB |
Output is correct |
2 |
Correct |
5 ms |
23132 KB |
Output is correct |
3 |
Correct |
4 ms |
23016 KB |
Output is correct |
4 |
Correct |
6 ms |
23132 KB |
Output is correct |
5 |
Correct |
4 ms |
23132 KB |
Output is correct |
6 |
Correct |
4 ms |
23172 KB |
Output is correct |
7 |
Correct |
3 ms |
23132 KB |
Output is correct |
8 |
Correct |
3 ms |
23132 KB |
Output is correct |
9 |
Correct |
3 ms |
23132 KB |
Output is correct |
10 |
Correct |
4 ms |
23132 KB |
Output is correct |
11 |
Correct |
3 ms |
23132 KB |
Output is correct |
12 |
Correct |
3 ms |
23132 KB |
Output is correct |
13 |
Correct |
3 ms |
23128 KB |
Output is correct |
14 |
Correct |
4 ms |
23388 KB |
Output is correct |
15 |
Correct |
109 ms |
34908 KB |
Output is correct |
16 |
Correct |
119 ms |
34640 KB |
Output is correct |
17 |
Correct |
141 ms |
34640 KB |
Output is correct |
18 |
Correct |
149 ms |
36688 KB |
Output is correct |
19 |
Correct |
127 ms |
36432 KB |
Output is correct |
20 |
Correct |
150 ms |
38500 KB |
Output is correct |
21 |
Correct |
115 ms |
34624 KB |
Output is correct |
22 |
Correct |
114 ms |
33972 KB |
Output is correct |
23 |
Correct |
117 ms |
33872 KB |
Output is correct |
24 |
Correct |
151 ms |
35892 KB |
Output is correct |
25 |
Correct |
139 ms |
38948 KB |
Output is correct |
26 |
Correct |
106 ms |
34384 KB |
Output is correct |
27 |
Correct |
112 ms |
33956 KB |
Output is correct |
28 |
Correct |
134 ms |
34132 KB |
Output is correct |
29 |
Correct |
131 ms |
35480 KB |
Output is correct |
30 |
Correct |
161 ms |
36916 KB |
Output is correct |
31 |
Correct |
109 ms |
34444 KB |
Output is correct |
32 |
Correct |
115 ms |
34132 KB |
Output is correct |
33 |
Correct |
121 ms |
34268 KB |
Output is correct |
34 |
Correct |
148 ms |
36036 KB |
Output is correct |
35 |
Correct |
141 ms |
38964 KB |
Output is correct |
36 |
Correct |
132 ms |
35916 KB |
Output is correct |