Efficient Collection Operations

Efficient Collection Operations

Preallocate capacity using Vec::with_capacity to prevent repeated reallocations:

fn main() {
    let mut fast_vec = Vec::with_capacity(1000);
    for i in 0..1000 {
        fast_vec.push(i * 2);
    }
    println!("Length: {}, Capacity: {}", fast_vec.len(), fast_vec.capacity());
}