Function counting_sort

pub fn counting_sort<F, T>(arr: &mut [T], min: usize, max: usize, key: F)
where
    F: Fn(&T) -> usize,
    T: Clone,

Counting sort

• arr - Collection of value to be sorted in place.
• min - Lower bound of the integer range.
• max - Upper bound of the integer range.
• key - Function extracting key witn the integer range from elements.