update prerequisites

content/0_Intro/2_Intro_Prerequisites.md

@@ -11,6 +11,20 @@ Here's what you should learn before reading these resources.
  
 These resources do not teach you how to code. We recommend you learn roughly the first half of AP Computer Science A before continuing. If you do not meet these prerequisites, you can go to the resources below to get started.
 
+Expected Knowledge:
+
+- Variables
+  - Data types
+- Reading Input
+- Writing Output
+- Loops
+- If/else
+- Logical operators
+- Functions
+  - Basic Recursion (a function calling itself)
+- Arrays
+  - Multidimensional Arrays
+
 ## Resources for Learning to Code
 
 [Sololearn](https://www.sololearn.com/) has courses on C++, Java, and Python. You don't have to complete the full course.
@@ -19,6 +33,8 @@ These resources do not teach you how to code. We recommend you learn roughly the
 
 ## Using C++
 
+You do not need to learn pointers (for now). Knowledge of structs and classes is useful but not required.
+
 Here's a basic C++ template you may find useful:
 
 ```cpp
@@ -27,6 +43,8 @@ Here's a basic C++ template you may find useful:
 using namespace std;
 
 int main() {
+    // these two lines open the file into the standard input/output,
+    // so you can just use cin/cout.
     freopen("file.in", "r", stdin);
     freopen("file.out", "w", stdout);