Java 性能竟然优于 Rust，哪里有问题呢？

近日 B 站看到概率问题：《连续抛 10000 次硬币，最多几连正的概率最大？》

使用擅长的 Java 模拟，共 10w 次实验，每次实验模拟投掷 1w 次，耗时 1080ms ；多次运行耗时相差不大。
同样的算法，用 Kimi 翻译成 Rust ，cargo build --release 生成可执行文件；但执行效率不如 Java ，且耗时 10x。
哪里有问题呢？

Java

public class TossStreakProbability { public static final int tosses = 10_000; // 10^4 public static final int iteratiOns= 100_000; // 10^5 public static void main(String[] args) { Instant start = Instant.now(); Map<Integer, Long> streakMap = new HashMap<>(); for (int i = 0; i < iterations; i++) { int maxStreak = maxStreak(); streakMap.put(maxStreak, streakMap.getOrDefault(maxStreak, 0L) + 1); } long total = streakMap.values().stream().mapToLong(Long::intValue).sum(); streakMap.forEach((key, value) -> System.out.printf( "Max: %d, count: %d, percent:%.2f%%\n", key, value, (value * 100.0) / total)); // print execute time in ms System.out.println("Execution time: " + (Instant.now().toEpochMilli() - start.toEpochMilli()) + "ms"); } public static int maxStreak() { int streak = 0, maxStreak = 0; var random = ThreadLocalRandom.current(); for (int i = 0; i < tosses; i++) { boolean current = random.nextBoolean(); if (current) { streak++; } else { streak = 0; } maxStreak = Math.max(maxStreak, streak); } return maxStreak; } } 

Rust

use std::collections::HashMap; use std::time::Instant; use rand::prelude::*; const TOSSES: i32 = 10_000; // 10^4 const ITERATIONS: i32 = 100_000; // 10^5 fn main() { let start = Instant::now(); let mut streak_map: HashMap<i32, i64> = HashMap::new(); for _ in 0..ITERATIONS { let max_streak = max_streak(); *streak_map.entry(max_streak).or_insert(0) += 1; } let total: i64 = streak_map.values().sum(); for (key, value) in &streak_map { println!("Max: {}, count: {}, percent: {:.2}%", key, value, (*value as f64 / total as f64) * 100.0); } // print execute time in ms let duration = start.elapsed(); println!("Execution time: {}ms", duration.as_millis()); } fn max_streak() -> i32 { let mut streak = 0; let mut max_streak = 0; let mut rand = thread_rng(); for _ in 0..TOSSES { let current = rand.gen_bool(0.5); if current { streak += 1; } else { streak = 0; } max_streak = std::cmp::max(max_streak, streak); } max_streak }