From 19d48444a85f19c2df39715c4d96eb0ef7502323 Mon Sep 17 00:00:00 2001
From: Nathan Wang <nathan.r.wang@gmail.com>
Date: Mon, 29 Jun 2020 16:09:25 -0700
Subject: [PATCH] hld

---
 content/6_Plat/HLD.mdx | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/content/6_Plat/HLD.mdx b/content/6_Plat/HLD.mdx
index 66304f5..c4040b4 100644
--- a/content/6_Plat/HLD.mdx
+++ b/content/6_Plat/HLD.mdx
@@ -14,8 +14,8 @@ import { Problem } from "../models";
 export const metadata = {
   problems: {
     sample: [
-      new Problem("CSES", "Company Queries II", "1688", "Intro", false, ["LCA"], ""),
-      new Problem("YS","Vertex Set Path Composite","vertex_set_path_composite", "Easy", false, ["HLD"], ""),
+      new Problem("CSES", "Company Queries II", "1688", "Intro", false, ["LCA"], "Pure implementation; see Benq's library code, it has a function for LCA. Though this problem can be solved with binary lifting as well, you should do it with HLD to get practice."),
+      new Problem("YS","Vertex Set Path Composite","vertex_set_path_composite", "Normal", false, ["HLD"], "Function order matters! Maintain two segment trees, one for going up and the other for going down the tree."),
     ],
     general: [
       new Problem("Gold", "Cow Land", "921", "Easy", false, ["Euler-Tree","PURS", "HLD"], ""),
@@ -34,12 +34,18 @@ export const metadata = {
 ## Tutorial
 
 <resources>
-  <resource source="cp-algo" title="HLD" url="https://cp-algorithms.com/graph/hld.html" starred>read this first to understand HLD</resource>
-  <resource source="CF" title="AI-Cash - HLD Implementation" url="blog/entry/22072" starred>read this second for HLD implementatoin</resource>
-  <resource source="CF" title="adamant - Easiest HLD with subtree queries" url="blog/entry/53170" starred></resource>
+  <resource source="cp-algo" title="HLD" url="https://cp-algorithms.com/graph/hld.html" starred>For an alternate implementation, see below</resource>
   <resource source="anudeep2011" title="HLD" url="https://blog.anudeep2011.com/heavy-light-decomposition/">explains what HLD is (but incomplete & overly complicated code)</resource>
 </resources>
 
+## Implementations
+
+<resources>
+  <resource source="CF" title="AI-Cash - HLD Implementation" url="blog/entry/22072" starred />
+  <resource source="CF" title="adamant - Easiest HLD with subtree queries" url="blog/entry/53170" starred>Not a complete HLD implementation</resource>
+  <resource source="Benq" title="Complete HLD Implementation" url="https://github.com/bqi343/USACO/blob/master/Implementations/content/graphs%20(12)/Trees%20(10)/HLD%20(10.3).h" starred>Complete HLD implementation following the first two articles (with minor modifications)</resource>
+</resources>
+
 ## Problems
 
 <problems-list problems={metadata.problems.general} />
\ No newline at end of file