A brief introduction to the odd even sorting algorithm and its implementation in Java array

Odd-even sorting is a kind of unique sorting. The basic idea is to arrange odd columns in 1 order, even columns in 1 order, odd columns in 1 order, and even columns in 1 order, until all of them are in order

For example,

For row array

[6 2 4 1 5 9]

The first time the odd column is compared, the odd column is compared to its neighbor even columns, such as 6 and 2,4 and 1,5 and 9

[6 2 4 1 5 9]

When you swap it out

[2 6 1 4 5 9]

The second time you compare even columns, you compare 6 to 1,5 to 5

[2 6 1 4 5 9]

When you swap it out

[2 1 6 4 5 9]

The third row is an odd column, and we chose 2,6, and 5 to compare with their neighbor columns

[2 1 6 4 5 9]

After exchanging

[1 2 4 6 5 9]

The fourth row of even columns

[1 2 4 6 5 9]

One exchange

[1 2 4 5 6 9]

Java implementation:

static void oddEvensort(int[] ary) { 
  // Parity sorting  
   
  boolean flag = true; 
  while (flag) { 
   boolean odd = false, even = false; 
   for (int i = 0; i < ary.length - 1; i+=2) { 
    if (ary[i] > ary[i + 1]) { 
     ary[i] = ary[i + 1] + 0 * (ary[i + 1] = ary[i]); 
     odd = true; 
    } 
   } 
   for (int i = 1; i < ary.length - 1; i+=2) { 
    if (ary[i] > ary[i + 1]) { 
     ary[i] = ary[i + 1] + 0 * (ary[i + 1] = ary[i]); 
     even = true; 
    } 
   } 
   flag = odd || even; // if false , indicating that no matter whether the sequence is odd or even, 1 There are no qualified comparisons  
  } 
 } 

flag = odd || even; If one of       is true, which means it is still swapping, then flag is only false if they are all false.
So flag = odd && even;       has one false, and it no longer cycles as a whole. Like bubble sort 1, you can reduce the last inner loop.