如何使用 chrono 查看我的排序算法每次迭代需要多长时间？

Question

I have to run my program a certain amount of times and want to determine the time to takes for each iteration to complete. I changed it to a smaller value to see the results but it shows me

0.002056
0.001183
0.000613
0.000922
0.000731

I'm a little unsure if this is how the results should look for bubble sort since it begins larger than the end of the results. Do these results seem accurate or am I calling my timer in a weird position?

if (sorting_type == 1) {
        for (int i = 0; i < 5; i++) {
            auto timer1 = chrono::high_resolution_clock::now();
            A->BubbleSort();
            auto timer2 = chrono::high_resolution_clock::now();
            chrono::duration<double, milli> duration_ms = timer2 - timer1;
            cout << duration_ms.count() << endl;
            
        }  
    }

Answer 1

You are repeatedly sorting the same set of data. This leads to Bubble Sort taking way less time after the first iteration. If your data looked like this before:

[6,2,8,1]

These steps would have to happen in the first iteration:

 <->
[2,6,8,1]
   <->
[2,6,8,1]
     <->
[2,6,1,8]
 <->
[2,6,1,8]
   <->
[2,1,6,8]
     <->
[2,1,6,8]
 <->
[1,2,6,8]
   <->
[1,2,6,8]
     <->
[1,2,6,8]
 <->
[1,2,6,8]
   <->
[1,2,6,8]
     <->
[1,2,6,8]

The other iterations would all just look like this:

 <->
[1,2,6,8]
   <->
[1,2,6,8]
     <->
[1,2,6,8]