fn main() {
    let fruits = vec!["apple", "banana", "cherry"];

    for (i, fruit) in fruits.iter().enumerate() {
        println!("{}. {}", i + 1, fruit);
    }

    // find with index
    let nums = vec![10, 20, 30, 40, 50];
    let found = nums.iter().enumerate().find(|(_, &v)| v > 25);
    println!("first > 25: {:?}", found);

    // collect into indexed map
    let indexed: Vec<(usize, &str)> = fruits.into_iter().enumerate().collect();
    println!("indexed: {:?}", indexed);
}