#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 7;
struct Edge {
int to, weight, id;
};
struct Query {
int type, x, y, z;
};
vector<vector<Edge>> adj;
vector<int> grapes;
vector<bool> hasGrape;
int n, q;
// Dijkstra's Algorithm for shortest path to nearest grape
vector<int> dijkstra() {
vector<int> dist(n + 1, INF);
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
for (int grape : grapes) {
dist[grape] = 0;
pq.emplace(0, grape);
}
while (!pq.empty()) {
auto [d, u] = pq.top();
pq.pop();
if (d > dist[u]) continue;
for (auto [v, weight, _] : adj[u]) {
if (dist[v] > dist[u] + weight) {
dist[v] = dist[u] + weight;
pq.emplace(dist[v], v);
}
}
}
return dist;
}
// Update edge weights
void updateEdge(int a, int b, int w) {
for (auto &edge : adj[a]) {
if (edge.to == b) {
edge.weight = w;
break;
}
}
for (auto &edge : adj[b]) {
if (edge.to == a) {
edge.weight = w;
break;
}
}
}
// Process queries
void processQueries(vector<Query> &queries) {
for (auto &query : queries) {
if (query.type == 1) {
int qi = query.x;
auto dist = dijkstra();
cout << (dist[qi] == INF ? -1 : dist[qi]) << "\n";
} else if (query.type == 2) {
int ui = query.x;
if (hasGrape[ui]) {
hasGrape[ui] = false;
grapes.erase(remove(grapes.begin(), grapes.end(), ui), grapes.end());
} else {
hasGrape[ui] = true;
grapes.push_back(ui);
}
} else if (query.type == 3) {
int ai = query.x, bi = query.y, wi = query.z;
updateEdge(ai, bi, wi);
}
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> q;
adj.resize(n + 1);
hasGrape.assign(n + 1, false);
for (int i = 0; i < n - 1; i++) {
int a, b, w;
cin >> a >> b >> w;
adj[a].push_back({b, w, i});
adj[b].push_back({a, w, i});
}
vector<Query> queries;
for (int i = 0; i < q; i++) {
int type, x, y = 0, z = 0;
cin >> type >> x;
if (type == 2) {
queries.push_back({type, x, 0, 0});
} else if (type == 3) {
cin >> y >> z;
queries.push_back({type, x, y, z});
} else if (type == 1) {
queries.push_back({type, x, 0, 0});
}
}
processQueries(queries);
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
592 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1483 ms |
11984 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1391 ms |
12788 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
766 ms |
12216 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2099 ms |
12100 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
592 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |