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150<snippet>
<content><![CDATA[
const int inf = 2e9;
int n, l;
vector<vector<int>> adj; //upd adj
int _q = 0; //update it to _q if wt ed tree is used
vector<vector<pair<int, int>>> wadj;
vector<int> wt;
int timer;
vector<int> tin, tout, depth;
vector<vector<int>> up, mx, mn;
vector<int> arr;
void dfs(int v, int p, int dep) //depth is extra,in case needed...
{
tin[v] = ++timer;
up[v][0] = p;
mx[v][0] = arr[v];
mn[v][0] = arr[v];
depth[v] = dep;
for (int i = 1; i <= l; ++i) {
up[v][i] = up[up[v][i - 1]][i - 1];
mx[v][i] = max(mx[v][i - 1], mx[up[v][i - 1]][i - 1]);
mn[v][i] = min(mn[v][i - 1], mn[up[v][i - 1]][i - 1]);
}
for (int u : adj[v]) {
if (u != p)
dfs(u, v, dep + 1);
}
tout[v] = ++timer;
}
void wdfs(int v, int p, int sofar)
{
wt[v] = sofar;
for (auto &[u, w] : wadj[v]) {
if (u != p)
wdfs(u, v, sofar + w);
}
}
// is u ancestor of v?
bool is_ancestor(int u, int v)
{
return tin[u] <= tin[v] && tout[u] >= tout[v];
}
int lca(int u, int v)
{
if (is_ancestor(u, v))
return u;
if (is_ancestor(v, u))
return v;
for (int i = l; i >= 0; --i) {
if (!is_ancestor(up[u][i], v))
u = up[u][i];
}
return up[u][0];
}
int distance(int u, int v) {
int anc = lca(u, v);
return abs(depth[u] - depth[anc]) + abs(depth[anc] - depth[v]);
}
int weight(int u, int v) {
int anc = lca(u, v);
return abs(wt[u] - wt[anc]) + abs(wt[anc] - wt[v]);
}
void preprocess(int root) {
n = adj.size();
tin.resize(n);
tout.resize(n);
depth.resize(n);
timer = 0;
l = ceil(log2(n));
up.assign(n, vector<int>(l + 1));
mx.assign(n, vector<int>(l + 1, -inf));
mn.assign(n, vector<int>(l + 1, inf));
dfs(root, root, 0);
if (_q) {
wt.resize(n);
wdfs(root, root, 0);
}
}
/*
* if edge has weight and edge path query need, then just do edgevsnode mapping
* and assign find node max query excluding lca.
*/
int maxQuery(int u, int v) {
int U, V;
int res = -inf;
int lca = u;
auto doo = [&](auto u, auto v) {
if (is_ancestor(v, u))return;
U = u, V = v;
for (int i = l; i >= 0 ; i--) {
if (!is_ancestor(up[V][i], u)) {
chmax(res, mx[V][i]);
V = up[V][i];
}
}
chmax(res, arr[V]);
lca = up[V][0];
};
doo(u, v);
doo(v, u);
// doing for ancestor which wasnt covered in both case [exclude this if edge path query).
chmax(res, arr[lca]);
return res;
}
int minQuery(int u, int v) {
int U, V;
int res = inf;
int lca;
auto doo = [&](auto u, auto v) {
if (is_ancestor(v, u))return;
U = u, V = v;
for (int i = l; i >= 0 ; i--) {
if (!is_ancestor(up[V][i], u)) {
chmin(res, mx[V][i]);
V = up[V][i];
}
}
chmin(res, arr[V]);
lca = up[V][0];
};
doo(u, v);
doo(v, u);
// doing for ancestor which wasnt covered in both case [exclude this if edge path query).
chmin(res, arr[lca]);
return res;
}
]]></content>
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<tabTrigger>min max binary lifting lca</tabTrigger>
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<scope>source.c++</scope>
</snippet>