APIO Rainbow + USACO Hill Walk

Author: bqi343

content/5_Plat/Sweep_Line.mdx

@@ -34,6 +34,15 @@ export const problems = {
 		),
 	],
 	seg: [
+		new Problem(
+			'Old Gold',
+			'Hill Walk',
+			'266',
+			'Normal',
+			false,
+			[],
+			''
+		),
 		new Problem(
 			'CEOI',
 			'Roads',

solutions/APIO 17-rainbow.mdx

@@ -41,15 +41,15 @@ To find $E$, $V$, and $R$, we can use a data structure that can handle 2D range
 
 However, the coordinates of the grid can get very large, so a simple 2D BIT or segment tree won't work here.
 
-To work around this, we can either use a 2D BIT with coordinate compression or a persistent segment tree. See [the section on offline 2D sum queries](/plat/2DRQ#2d-offline-sum-queries) for more details.
+To work around this, we can either use a 2D BIT with coordinate compression or a persistent segment tree. See the sections on [offline 2D sum queries](/plat/2DRQ#2d-offline-sum-queries) or [persistent segment trees](https://usaco.guide/adv/persistent) for more details.
 
-## Complexity
+## Code
 
-Time: $O(N \log^2 N)$.
+With a persistent segment tree.
 
-Memory: $O(N \log N)$.
+**Time:** $\mathcal{O}(N \log N)$
 
-## Code
+**Memory:** $\mathcal{O}(N \log N)$
 
 ```cpp
 #include "rainbow.h"