# Exercise: Vec Statistics Calculator

**Concepts practiced:** Vec operations, HashMap for counting, basic math functions
**Objective:** Build a simple stats calculator that takes a list of numbers and returns basic statistics

## Requirements:
- Create a function `calculate_stats(numbers: Vec<i32>) -> (f64, i32, i32)` that returns (mean, median, mode)
- Use Vec sorting for median calculation
- Use HashMap for mode calculation (most frequent number)
- Handle edge cases (empty vec should panic with clear message)

## Success criteria:
- Code compiles and runs
- Test with `vec![1, 2, 3, 3, 4, 5]` returns approximately `(3.0, 3, 3)`

## Stretch goal:
Return a struct instead of tuple for better readability

## Getting Started:
1. `cd exercises`
2. `cargo new vec-stats`
3. `cd vec-stats`
4. Implement the function in `src/main.rs` or `src/lib.rs`
5. Test with the example input

Expected time: 30-45 minutes