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vector<vector<int>> adjlist();
vector<int> visited();
vector<int> first();
vector<int> depth();
void initLCA(int gi, int d, int& c) {
visited[c] = gi, depth[c] = d, first[gi] = min(c, first[gi]), c++;
for(int gn : adjlist[gi]) {
initLCA(gn, d+1, c);
visited[c] = gi, depth[c] = d, c++;
}}
int getLCA(int a, int b) {
return visited[query(min(first[a], first[b]), max(first[a], first[b]))];
}
void exampleUse() {
int c = 0;
visited = vector<int>(2*adjlist.size());
first = vector<int>(adjlist.size(), 2*adjlist.size());
depth = vector<int>(2*adjlist.size());
initLCA(0, 0, c);
init(depth);
}
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