java - 为冒泡排序执行计时

Question

我希望能够看到冒泡排序对数组中的所有元素进行排序需要多长时间。如何测量时间？

public class Bubble {
    static int[] nums = {5, 4, 3, 2, 1}; 

    public static void main(String[] args) {
        bubble(nums);
        for(int i=0; i<nums.length; i++){
            System.out.print(nums[i] + " ");
        }
    }

    // bubble sort
    public static void bubble(int[] unsorted){
        int temp;
        boolean sorted = false;
        int length = unsorted.length;

        while(!sorted){
            sorted = true;

            for(int i=0; i<length-1; i++){
                if(unsorted[i] > unsorted[i+1]){
                    temp = unsorted[i];
                    unsorted[i] = unsorted[i+1];
                    unsorted[i+1] = temp;
                    sorted = false;
                }
            }
        }
    }
}

Answer 1

摘自Diastropism对how do I time a methods excecution in java的回答:

There is always the old-fashioned way:

long startTime = System.nanoTime();
methodToTime();
long endTime = System.nanoTime();

long duration = endTime - startTime;