use std::collections::HashMap;
fn process_data(data: Vec<i32>) -> HashMap<i32, i32> {
    let mut result = HashMap::new();
    for (index, value) in data.iter().enumerate() {
        result.insert(index as i32, *value * 2);
    }
    result
}
#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn test_process_data() {
        let input = vec![1, 2, 3, 4, 5];
        let result = process_data(input);
        assert_eq!(result.get(& 0), Some(& 2));
        assert_eq!(result.get(& 1), Some(& 4));
    }
}