diff --git a/content/1_Intro/Intro_Problems.md b/content/1_Intro/Intro_Problems.md
index 0c755a9..9b383c6 100644
--- a/content/1_Intro/Intro_Problems.md
+++ b/content/1_Intro/Intro_Problems.md
@@ -1,7 +1,7 @@
---
slug: /intro/problems
title: Introductory Problems
-author: Nathan Wang
+author: Nathan Wang, Benjamin Qi
problems:
- bronze_promote
- bronze_word
diff --git a/content/4_Silver/3_Silver_Sorting.md b/content/4_Silver/3_Silver_Sorting.md
index 9044930..761ec78 100644
--- a/content/4_Silver/3_Silver_Sorting.md
+++ b/content/4_Silver/3_Silver_Sorting.md
@@ -8,9 +8,7 @@ prerequisites:
- Silver - Containers
---
-
- Description: Todo
-
++ more practice with ordered map / set?
diff --git a/content/4_Silver/5_Silver_2P.md b/content/4_Silver/5_Silver_2P.md
index 9578f65..a0cdfff 100644
--- a/content/4_Silver/5_Silver_2P.md
+++ b/content/4_Silver/5_Silver_2P.md
@@ -21,7 +21,6 @@ prerequisites:
- CSES
- [Sum of Two Values](https://cses.fi/problemset/task/1640)
- - [Maximum Subarray Sum](https://cses.fi/problemset/task/1643) (<- let's not lump this in w/ two pointers?)
- USACO
- [Silver - Diamond Collector](http://usaco.org/index.php?page=viewproblem2&cpid=643)
- sort and then use 2P
diff --git a/content/4_Silver/6_Silver_Psum.md b/content/4_Silver/6_Silver_Psum.md
index fe0859d..31af665 100644
--- a/content/4_Silver/6_Silver_Psum.md
+++ b/content/4_Silver/6_Silver_Psum.md
@@ -5,7 +5,7 @@ author: Eric Wei (incomplete)
order: 6
---
-> Given an array of size $N$, answer $Q$ queries of the following form: Find the sum of all elements between indices $i$ and $j$.
+> Given an array $A_1,A_2,\ldots,A_N$, answer $Q$ queries of the following form: compute $A_L+A_{L+1}+\cdots+A_R$.
@@ -23,6 +23,10 @@ This technique is also known as *cumulative sum* or *partial sums*.
## Extensions
+### Max Subarray Sum
+
+[Maximum Subarray Sum](https://cses.fi/problemset/task/1643)
+
### 2D Prefix Sums
Given a 2-dimensional array of size $NxM$, answer $Q$ queries of the following form: Find the sum of all elements within the rectangle of indices $(x1,y1)$ to $(x2,y2)$.
@@ -46,6 +50,7 @@ On the other hand, XOR is its own inverse operation...
- [CSES Range XOR Queries](https://cses.fi/problemset/task/1650)
### More Complex Applications
+
Instead of storing just the values themselves, you can also take a prefix sum over $i\cdot a_i$, or $10^i \cdot a_i$, for instance.
- (find iota ps problem)
diff --git a/content/6_Plat/11_DP_Ranges.md b/content/6_Plat/11_DP_Ranges.md
index bb423e6..92bb7e2 100644
--- a/content/6_Plat/11_DP_Ranges.md
+++ b/content/6_Plat/11_DP_Ranges.md
@@ -8,6 +8,8 @@ prerequisites:
- Gold - Introduction to Dynamic Programming
---
+
+
## Problems
* [Gold - 248](http://www.usaco.org/index.php?page=viewproblem2&cpid=647)