Why does sorting take so long?

Question

I'm currently trying to learn Rust syntax while solving small tasks. I compare runtime as a health check if I use the language correctly.

One task:

• Create an array of 10,000,000 random numbers in the range 0 - 1,000,000,000
• Sort and measure time
• Print the time it is sorted

I got the following results:

| #   | Language             | Speed  | LOCs |
| --- | -------------------- | ------ | ---- |
| 1   | C++ (with -O3)       | 1.36s  | 1    |
| 2   | Python (with PyPy)   | 3.14s  | 1    |
| 3   | Ruby                 | 5.04s  | 1    |
| 4   | Go                   | 6.17s  | 1    |
| 5   | C++                  | 7.95s  | 1    |
| 6   | Python (with Cython) | 11.51s | 1    |
| 7   | PHP                  | 36.28s | 1    |

Now I have written the following Rust code:

rust.rs

extern crate rand;
extern crate time;

use rand::Rng;
use time::PreciseTime;

fn main() {
    let n = 10000000;
    let mut array = Vec::new();

    let mut rng = rand::thread_rng();
    for _ in 0..n {
        //array[i] = rng.gen::<i32>();
        array.push(rng.gen::<i32>());
    }

    // Sort
    let start = PreciseTime::now();
    array.sort();
    let end = PreciseTime::now();

    println!("{} seconds for sorting {} integers.", start.to(end), n);
}

with the following Cargo.toml :

[package]
name = "hello_world" # the name of the package
version = "0.0.1"    # the current version, obeying semver
authors = [ "[e-mail]" ]
[[bin]]
name = "rust"
path = "rust.rs"
[dependencies]
rand = "*" # Or a specific version
time = "*"

I compiled it with cargo run rust.rsand ran the binary. He outputs

PT18.207168155S seconds for sorting 10000000 integers.

Please note that this is much slower than Python. I think I'm doing something wrong. (The full code for rust and other languages ​​is here if you are interested.)

Rust? ?

Answer 1

, cargo run:

PT11.634640178S seconds for sorting 10000000 integers.

cargo run --release ( ) :

PT1.004434739S seconds for sorting 10000000 integers.