#!/usr/bin/env bash
# Check if type argument is provided
if [ $# -eq 0 ]; then
    echo "Error: Type argument is required"
    echo "Usage: $0 <dis|hw> [max_number]"
    echo "Examples:"
    echo "  $0 dis 15"
    echo "  $0 hw 10"
    exit 1
fi
# Parse arguments
TYPE=$1
MAX_NUM=${2:-11}
# Validate type parameter
if [[ "$TYPE" != "dis" && "$TYPE" != "hw" ]]; then
    echo "Error: Type must be 'dis' or 'hw'"
    echo "Usage: $0 <dis|hw> [max_number]"
    exit 1
fi
# Create download directory
DOWNLOAD_DIR="cs170_${TYPE}"
mkdir -p "$DOWNLOAD_DIR"
cd "$DOWNLOAD_DIR"
echo "Starting download of CS170 ${TYPE^^} files (1-$MAX_NUM)..."
echo "Download directory: $DOWNLOAD_DIR"
echo "----------------------------------------"
DOWNLOADED=0
FAILED=0
# Download files and solutions
for i in $(seq 1 $MAX_NUM); do
    # Format number as two digits (01, 02, ...)
    num=$(printf "%02d" $i)
    # Download main file
    file_url="https://cs170.org/assets/pdf/${TYPE}${num}.pdf"
    echo -n "Downloading ${TYPE}${num}.pdf ... "
    if wget -q "$file_url" 2>/dev/null; then
        echo "✓"
        ((DOWNLOADED++))
    else
        echo "✗ (not found)"
        ((FAILED++))
    fi
    # Download solution file
    sol_url="https://cs170.org/assets/pdf/${TYPE}${num}-sol.pdf"
    echo -n "Downloading ${TYPE}${num}-sol.pdf ... "
    if wget -q "$sol_url" 2>/dev/null; then
        echo "✓"
        ((DOWNLOADED++))
    else
        echo "✗ (not found)"
        ((FAILED++))
    fi
done
echo "----------------------------------------"
echo "Download complete!"
echo "Success: $DOWNLOADED files"
echo "Failed/Not found: $FAILED files"
echo "Files saved in: $(pwd)"

# Berkeley CS170 Assets Download Script
A simple bash script to automatically download discussion worksheets (dis) and homework assignments (hw) from Berkeley's CS170 (Efficient Algorithms and Intractable Problems) course.
## Features
- Download discussion worksheets or homework assignments
- Automatically downloads both problem sets and solutions
- Skips files that don't exist on the server
- Customizable download range
- Organizes files into separate directories
## Requirements
- `bash`
- `wget`
## Usage
```bash
./download-Berkeley-CS170.sh <type> [max_number]
```
### Parameters
- `<type>` (required): Type of files to download
  - `dis` - Discussion worksheets
  - `hw` - Homework assignments
- `[max_number]` (optional): Maximum number to download (default: 11)
  - Downloads from 01 to the specified number
### Examples
Download discussion worksheets 01-11 (default):
```bash
./download-Berkeley-CS170.sh dis
```
Download discussion worksheets 01-15:
```bash
./download-Berkeley-CS170.sh dis 15
```
Download homework assignments 01-10:
```bash
./download-Berkeley-CS170.sh hw 10
```
## Output
Files are downloaded to directories based on type:
- Discussion worksheets: `cs170_dis/`
- Homework assignments: `cs170_hw/`
For each number, the script downloads:
- Main file: `dis##.pdf` or `hw##.pdf`
- Solution file: `dis##-sol.pdf` or `hw##-sol.pdf`
Files that don't exist on the server are automatically skipped.
## Source
Files are downloaded from: `https://cs170.org/assets/pdf/`