From f6e375290e896b95d7c4bbee466a12efa19fc5bb Mon Sep 17 00:00:00 2001
From: Bruno Freitas Tissei <bft15@inf.ufpr.br>
Date: Mon, 26 Aug 2019 11:24:14 -0300
Subject: [PATCH] Small fixes and improvements
Signed-off-by: Bruno Freitas Tissei <bft15@inf.ufpr.br>
---
algorithms/graph/hld.cpp | 4 ++--
algorithms/graph/lca.cpp | 16 +++++++---------
2 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/algorithms/graph/hld.cpp b/algorithms/graph/hld.cpp
index b6b58e4..73908ce 100644
--- a/algorithms/graph/hld.cpp
+++ b/algorithms/graph/hld.cpp
@@ -88,14 +88,14 @@ struct HLD {
for (; head[a] != head[b]; b = par[head[b]]) {
if (dep[head[a]] > dep[head[b]])
swap(a, b);
- ans = seg.op(ans, seg.query(pos[head[b]], pos[b]));
+ ans = seg.func(ans, seg.query(pos[head[b]], pos[b]));
}
if (dep[a] > dep[b])
swap(a, b);
// Remove "+ 1" when values are associated with vertices
- return seg.op(ans, seg.query(pos[a] + 1, pos[b]));
+ return seg.func(ans, seg.query(pos[a] + 1, pos[b]));
}
// Updates value of i-th edge (or vertice)
diff --git a/algorithms/graph/lca.cpp b/algorithms/graph/lca.cpp
index 51bd1cf..d16ddec 100644
--- a/algorithms/graph/lca.cpp
+++ b/algorithms/graph/lca.cpp
@@ -22,10 +22,12 @@
vector<ii> graph[MAX];
int par[MAX][LOG], cost[MAX][LOG];
+template <class F = function<T(const T&, const &T)>>
struct LCA {
+ F func;
vector<int> h;
- LCA(int N) : h(N)
+ LCA(int N, F &func) : h(N), func(func)
{ init(); }
void init() {
@@ -34,10 +36,6 @@ struct LCA {
dfs(0); // root is 0
}
- int op(int a, int b) {
- return a + b; // or max(a, b)
- }
-
void dfs(int v, int p = -1, int c = 0) {
par[v][0] = p;
cost[v][0] = c;
@@ -48,7 +46,7 @@ struct LCA {
for (int i = 1; i < LOG; ++i)
if (par[v][i - 1] != -1) {
par[v][i] = par[par[v][i - 1]][i - 1];
- cost[v][i] = op(cost[v][i], op(cost[v][i-1],
+ cost[v][i] = func(cost[v][i], func(cost[v][i-1],
cost[par[v][i-1]][i-1]));
}
@@ -65,7 +63,7 @@ struct LCA {
for (int i = LOG - 1; i >= 0; --i)
if (par[a][i] != -1 && h[par[a][i]] >= h[b]) {
- ans = op(ans, cost[a][i]);
+ ans = func(ans, cost[a][i]);
a = par[a][i];
}
@@ -79,7 +77,7 @@ struct LCA {
for (int i = LOG - 1; i >= 0; --i)
if (par[a][i] != -1 && par[a][i] != par[b][i]) {
- ans = op(ans, op(cost[a][i], cost[b][i]));
+ ans = func(ans, func(cost[a][i], cost[b][i]));
a = par[a][i];
b = par[b][i];
}
@@ -88,7 +86,7 @@ struct LCA {
if (a == b)
return ans;
else
- return op(ans, op(cost[a][0], cost[b][0]));
+ return func(ans, func(cost[a][0], cost[b][0]));
#else
return par[a][0];
#endif
--
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