rust-tutor/exercises/vec-stats/vec-stats-exercise.md

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