如何在Java中证明一种算法比另一种算法更快

Question

Java中是否有任何东西可以让我获取代码snippit并允许我确切地查看执行它需要多少"滴答".我想证明我写的算法比另一个更快.

Answer 1

"蜱虫"？不.我建议您每次运行几次并比较平均结果:

public class AlgorithmDriver {
    public static void main(String [] args) {
        int numTries = 1000000;
        long begTime = System.currentTimeMillis();
        for (int i = 0; i < numTries; ++i) {
            Algorithm.someMethodCall();
        }
        long endTime = System.currentTimeMillis();
        System.out.printf("Total time for %10d tries: %d ms\n", numTries, (endTime-begTime));
    }
}