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| #include <bits/stdc++.h>
using namespace std;
int N, M;
const int SZ = 50001;
vector<vector<int>> adj(SZ);
vector<pair<int, int>> edges(SZ);
vector<set<pair<int, int>>> nodeset(SZ);
vector<int> parent(SZ);
vector<int> ans(SZ);
int dfs(int n, int p) {
// merge small 2 large alg
for (auto c : adj[n]) {
if (c != p) {
parent[c] = n;
int csz = dfs(c, n);
if (csz > nodeset[n].size()) swap(nodeset[n], nodeset[c]);
for (auto s : nodeset[c]) {
if (nodeset[n].count(s)) {
// disruption question specialty
// if the same edge in both sets,
// the edge is internal to tree (therefore remove)
nodeset[n].erase(s);
}
else {
nodeset[n].insert(s);
}
}
}
}
if (nodeset[n].size() == 0) {
ans[n] = -1;
}
else {
ans[n] = nodeset[n].begin()->first;
}
return nodeset[n].size();
}
int main() {
ifstream cin("disrupt.in");
ofstream cout("disrupt.out");
cin >> N >> M;
adj.resize(N + 1);
for (int i = 0; i < N - 1; i++) {
int p, q;
cin >> p >> q;
edges[i] = {p, q};
adj[p].push_back(q);
adj[q].push_back(p);
}
for (int i = 0; i < M; i++) {
int p, q, r;
cin >> p >> q >> r;
nodeset[p].insert({r, i});
nodeset[q].insert({r, i});
}
dfs(1, -1);
for (int i = 0; i < N - 1; i++) {
int fv = edges[i].first, sv = edges[i].second;
if (parent[sv] == fv) swap(sv, fv);
cout << ans[fv] << endl;
}
}
|