Question

How to extract the unique integers from a vector excluding duplicates in Rust

Answer 1

use std::collections::HashMap;

fn get_unique_exclude_duplicates(v: Vec<i32>) -> Vec<i32> {
    let mut frequency: HashMap<i32, i32> = HashMap::new();

    // Count occurrences of each number
    for &num in &v {
        *frequency.entry(num).or_insert(0) += 1;
    }

    // Collect numbers that appear only once
    let result: Vec<i32> = v.into_iter()
        .filter(|&num| frequency[&num] == 1)
        .collect();

    result
}

fn main() {
    let v = vec![1, 2, 3, 5, 8, 3, 1, 1, 0, 6, 5, 7, 3, 1, 4, 9];

    let unique_values = get_unique_exclude_duplicates(v);

    println!(
        "Unique values (excluding duplicates): {}",
        unique_values.iter().map(|x| x.to_string()).collect::<Vec<String>>().join(" ")
    );
}


      
/*
run:

Unique values (excluding duplicates): 2 8 0 6 7 4 9
     
*/

 

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