use std::time::{Instant, Duration};
use std::thread;

fn main() {
    let start = Instant::now();

    // 模拟耗时操作
    thread::sleep(Duration::from_millis(100));

    let elapsed = start.elapsed();
    println!("耗时: {:?}", elapsed);

    // Duration 运算
    let d1 = Duration::from_secs(1);
    let d2 = Duration::from_millis(500);
    let total = d1 + d2;
    println!("总时长: {:?}", total);
}

use std::time::SystemTime;

fn main() {
    let now = SystemTime::now();
    println!("当前时间: {:?}", now);

    let duration = now.duration_since(SystemTime::UNIX_EPOCH).unwrap();
    println!("Unix 时间戳: {} 秒", duration.as_secs());
}

use std::time::Instant;

fn fibonacci(n: u64) -> u64 {
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

fn main() {
    let start = Instant::now();
    let result = fibonacci(30);
    let elapsed = start.elapsed();
    println!("fibonacci(30) = {}, 耗时: {:?}", result, elapsed);
}

use std::time::{Instant, Duration};

fn main() {
    let interval = Duration::from_secs(1);
    let mut last = Instant::now();

    for i in 0..5 {
        while last.elapsed() < interval {
            std::thread::yield_now();
        }
        println!("tick {}", i);
        last = Instant::now();
    }
}