rust count distinct elements in list

To count the distinct elements in a list in Rust, you can use the HashSet data structure. Here's an example code snippet:

use std::collections::HashSet;

fn main() {
    let list = vec![1, 2, 3, 2, 1, 4, 5, 4];
    let distinct_elements: HashSet<_> = list.into_iter().collect();
    let count = distinct_elements.len();
    println!("Number of distinct elements: {}", count);
}

In this code, we create a HashSet called distinct_elements and use the into_iter() method to convert the list into an iterator. We then collect the iterator into the HashSet, which automatically removes duplicate elements. Finally, we get the count of distinct elements using the len() method of the HashSet.

Please note that you need to add use std::collections::HashSet; at the beginning of your code to import the HashSet data structure.

I hope this helps! Let me know if you have any further questions.