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Update graph/hld.cc 

Signed-off-by: subcrip <contact@subc.rip>
This commit is contained in:
subcrip 2024-05-22 11:48:26 +08:00
parent 7174c21f8c
commit 89e07ebc8a
1 changed files with 59 additions and 6 deletions
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65
graph/hld.cc
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@ -1,13 +1,18 @@
namespace HLD { template <typename Info, typename Tag>
struct HLD {
struct node_info { struct node_info {
int father, depth, hson, size, head, dfn = -1; int father, depth, hson, size, head, dfn = -1;
}; };
int n;
vector<int> seq;
vector<node_info> info;
segtree<Info, Tag> tr;
// returns: (dfs sequence, node info) // returns: (dfs sequence, node info)
// node numbering starts from `1` // node numbering starts from `1`
// if `dfn(v) == -1`, then node `v` is never accessed. // if `dfn(v) == -1`, then node `v` is never accessed.
pair<vector<int>, vector<node_info>> work(const vector<vector<int>>& ch, int root = 0) { HLD(const vector<vector<int>>& ch, const vector<Info>& init, int root = 0) : n(ch.size() - 1), seq(), info(n + 1), tr(n + 1) {
int n = ch.size() - 1;
vector<int> seq;
vector<node_info> res(n + 1); vector<node_info> res(n + 1);
auto dfs1 = [&] (auto dfs1, int v, int pa) -> void { auto dfs1 = [&] (auto dfs1, int v, int pa) -> void {
res[v].father = pa; res[v].father = pa;
@ -38,6 +43,54 @@ namespace HLD {
} }
}; };
dfs2(dfs2, root, root); dfs2(dfs2, root, root);
return { seq, res }; info = res;
for (int i = 1; i <= n; ++i) {
tr.set(info[i].dfn, init[i]);
} }
} }
void set(int v, const Info& t) {
tr.set(info[v].dfn, t);
}
void apply(int v, const Tag& t) {
tr.apply(info[v].dfn, t);
}
Info query(int v) {
return tr.query(info[v].dfn);
}
void path_apply(int u, int v, const Tag& t) {
while (info[u].head != info[v].head) {
if (info[info[u].head].depth < info[info[v].head].depth) {
swap(u, v);
}
tr.range_apply(info[info[u].head].dfn, info[u].dfn, t);
}
if (info[u].depth < info[v].depth) swap(u, v);
tr.range_apply(info[v].dfn, info[u].dfn);
}
Info path_query(int u, int v) {
Info res;
while (info[u].head != info[v].head) {
if (info[info[u].head].depth < info[info[v].head].depth) {
swap(u, v);
}
res = res + tr.range_query(info[info[u].head].dfn, info[u].dfn);
}
if (info[u].depth < info[v].depth) swap(u, v);
res = res + tr.range_query(info[v].dfn, info[u].dfn);
return res;
}
void subtree_apply(int v, const Tag& t) {
tr.range_apply(info[v].dfn, info[v].dfn + info[v].size - 1, t);
}
Info subtree_query(int v) {
return tr.range_query(info[v].dfn, info[v].dfn + info[v].size - 1);
}
};