count-invert

count-invert is a Rust crate providing utility functions for counting the occurrences of elements in a vector and inverting a HashMap based on those counts. This crate leverages the itertools crate to offer robust and efficient functionalities for common data manipulation tasks.

Features

• Convert a vector into a HashMap with element counts.
• Invert a HashMap to map counts to vectors of elements.
• Combine both functionalities to create a HashMap mapping counts to vectors of elements directly from a vector.

Installation

Add count-invert to your Cargo.toml:

[dependencies]
count-invert = "0.1.0"

Usage

Here's how to use the count-invert crate:

into_counts Convert a vector into a HashMap where the keys are the elements and the values are their counts.

use count_invert::into_counts;
use std::collections::HashMap;

let vec = vec![1, 2, 2, 3, 3, 3];
let counts: HashMap<i32, usize> = into_counts(vec);
println!("{:?}", counts); // Output: {1: 1, 2: 2, 3: 3}

invert_map Invert a HashMap such that the keys become the values and the values become the keys.

use count_invert::invert_map;
use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, 2);
map.insert(2, 2);
map.insert(3, 3);

let inverted: HashMap<usize, Vec<i32>> = invert_map(map);
println!("{:?}", inverted); // Output: {2: [1, 2], 3: [3]}

into_count_map Convert a vector into a HashMap where the keys are the counts of elements and the values are vectors of elements with those counts.

use count_invert::into_count_map;
use std::collections::HashMap;

let vec = vec![1, 2, 2, 3, 3, 3];
let count_map: HashMap<usize, Vec<i32>> = into_count_map(vec);
println!("{:?}", count_map); // Output: {1: [1], 2: [2], 3: [3]}

Contributing

Contributions are welcome! Please submit pull requests or open issues to suggest improvements or report bugs.

License

This project is licensed under the MIT License. See the LICENSE file for details.