شرح خوارزمية الترتيب بالدمج Merge Sort

package main
import "fmt"
func merge(a []int, b []int) []int {
  var r = make([]int, len(a) + len(b))
  var i = 0
  var j = 0
  for i < len(a) && j < len(b) {

    if a[i] <= b[j] {
      r[i+j] = a[i]
      i++
    } else {
      r[i+j] = b[j]
      j++
    }

  }
  for i < len(a) { r[i+j] = a[i]; i++ }
  for j < len(b) { r[i+j] = b[j]; j++ }
  return r

}
func Mergesort(items []int) []int {
  if len(items) < 2 {
    return items

  }
  var middle = len(items) / 2
  var a = Mergesort(items[:middle])
  var b = Mergesort(items[middle:])
  return merge(a, b)

}
func main () {
  fmt.Print(Mergesort([]int{ 10, 9, 8, 4, 5, 6, 13, 55, 72, 86, 100, 123, 7, 3, 2, 1 }), "\n")

}

package Sorts;
import static Sorts.SortUtils.print;
class MergeSort implements SortAlgorithm {
    @Override
    @SuppressWarnings("unchecked")
    public <T extends Comparable<T>> T[] sort(T[] unsorted) {
        T[] tmp = (T[]) new Comparable[unsorted.length];
        doSort(unsorted, tmp, 0, unsorted.length - 1);
        return unsorted;
    }
    private  static <T extends Comparable<T>> void doSort(T[] arr, T[] temp, int left, int right) {
        if (left < right) {
            int mid = left + (right - left) / 2;
            doSort(arr, temp, left, mid);
            doSort(arr,  temp,mid + 1, right);
            merge(arr, temp, left, mid, right);
        }
   }
    private static <T extends Comparable<T>> void merge(T[] arr, T[] temp, int left, int mid, int right) {
        System.arraycopy(arr, left, temp, left, right - left + 1);
        int i= left;
        int j = mid + 1;
        int k = left;
        while (i <= mid && j <= right) {
            if (temp[i].compareTo(temp[j]) <= 0) {
                arr[k++] = temp[i++];
            }
            else {
                arr[k++] = temp[j++];
            }
        }
        while (i <= mid) {
            arr[k++] = temp[i++];
        }
 while (j <= right) {
     arr[k++] = temp[j++];
 }
    }
    // Driver program
    public static void main(String[] args) {
        // Integer Input
        Integer[] arr = {10, 9, 8, 4, 5, 6, 13, 55, 72, 86, 100, 123, 7, 3, 2, 1};
        MergeSort mergeSort = new MergeSort();
        mergeSort.sort(arr);
        // Output => 1    4    6 9 12 23 54 78 231
        print(arr);
        // String Inpu
//        String[] stringArray = {"c", "a", "e", "b","d"};
//        mergeSort.sort(stringArray);
        //Output => a b c d e
//        print(stringArray);
    }
}

def merge_sort(LIST):
    start = []
    end = []
    while len(LIST) > 1:
        a = min(LIST)
        b = max(LIST)
        start.append(a)
        end.append(b)
        LIST.remove(a)
        LIST.remove(b)
    if LIST: start.append(LIST[0])
    end.reverse()
    return (start + end)
print(merge_sort({10, 9, 8, 4, 5, 6, 13, 55, 72, 86, 100, 123, 7, 3, 2, 1}))