From d9a61d211b3f9ab45c7787f399efa59ffe9e4bff Mon Sep 17 00:00:00 2001
From: KowerKoint <kowerkoint@gmail.com>
Date: Tue, 6 Aug 2024 17:36:36 +0900
Subject: [PATCH] weighted lca

---
 cpp/tree.hpp                | 31 ++++++++++++++++++++++++++++---
 test/yukicoder-898.test.cpp | 22 ++++++++++++++++++++++
 2 files changed, 50 insertions(+), 3 deletions(-)
 create mode 100644 test/yukicoder-898.test.cpp

diff --git a/cpp/tree.hpp b/cpp/tree.hpp
index 26e00b4..7ffd8b4 100644
--- a/cpp/tree.hpp
+++ b/cpp/tree.hpp
@@ -135,7 +135,6 @@ struct RootedTree : private Tree<Cost> {
     using Tree<Cost>::operator[];
     using Tree<Cost>::edges;
     using Tree<Cost>::shortest_path;
-    using Tree<Cost>::Tree;
 
     int root; //!< 根
     std::vector<Edge> par; //!< 親へ向かう辺
@@ -262,7 +261,6 @@ struct DoublingClimbTree : private RootedTree<Cost> {
     using RootedTree<Cost>::operator[];
     using RootedTree<Cost>::edges;
     using RootedTree<Cost>::shortest_path;
-    using RootedTree<Cost>::RootedTree;
     using RootedTree<Cost>::root;
     using RootedTree<Cost>::par;
     using RootedTree<Cost>::child;
@@ -296,6 +294,34 @@ struct DoublingClimbTree : private RootedTree<Cost> {
         build();
     }
     
+    /**
+     * @brief 親の頂点のリストから根が0のダブリング済み根付き木を構築するコンストラクタ
+     * 
+     * @param par_ 頂点0以外の親の頂点のリスト
+     * @param padding = -1 parの頂点番号をいくつずらすか
+     */
+    DoublingClimbTree(const std::vector<int>& par_, int padding = -1) : RootedTree<Cost>(par_, padding) {
+        build();
+    }
+    /**
+     * @brief Treeからダブリング済み根付き木を構築するコンストラクタ(コピー)
+     *
+     * @param tree Tree
+     * @param root 根
+     */
+    DoublingClimbTree(const Tree<Cost>& tree, int root) : RootedTree<Cost>(tree, root) {
+        build();
+    }
+    /**
+     * @brief Treeからダブリング済み根付き木を構築するコンストラクタ(ムーブ)
+     *
+     * @param tree Tree
+     * @param root 根
+     */
+    DoublingClimbTree(Tree<Cost>&& tree, int root) : RootedTree<Cost>(std::move(tree), root) {
+        build();
+    }
+    
     /**
      * @brief 頂点uからk回を根の方向に遡った頂点
      * 
@@ -321,7 +347,6 @@ struct DoublingClimbTree : private RootedTree<Cost> {
     int lca(int u, int v) const {
         if(this->unweighted_depth[u] > this->unweighted_depth[v]) std::swap(u, v);
         v = climb(v, this->unweighted_depth[v] - this->unweighted_depth[u]);
-        if(this->unweighted_depth[u] > this->unweighted_depth[v]) u = climb(u, this->unweighted_depth[u] - this->unweighted_depth[v]);
         if(u == v) return u;
         for(int i = h - 1; i >= 0; i--) {
             int nu = doubling_par[i][u];
diff --git a/test/yukicoder-898.test.cpp b/test/yukicoder-898.test.cpp
new file mode 100644
index 0000000..aa54015
--- /dev/null
+++ b/test/yukicoder-898.test.cpp
@@ -0,0 +1,22 @@
+#define PROBLEM "https://yukicoder.me/problems/no/898"
+
+#include "../cpp/tree.hpp"
+#include <bits/stdc++.h>
+using namespace std;
+using ll = long long;
+
+int main() {
+    int n; cin >> n;
+    Tree<ll> tr(n); tr.read(0, true);
+    DoublingClimbTree<ll> dct(tr, 0);
+    int q; cin >> q;
+    while(q--) {
+        array<int, 3> xyz;
+        for(int i = 0; i < 3; i++) cin >> xyz[i];
+        int lca01 = dct.lca(xyz[0], xyz[1]);
+        int lca02 = dct.lca(xyz[0], xyz[2]);
+        int lca12 = dct.lca(xyz[1], xyz[2]);
+        int center = lca01 ^ lca02 ^ lca12;
+        cout << dct.dist(xyz[0], center) + dct.dist(xyz[1], center) + dct.dist(xyz[2], center) << endl;
+    }
+}