C++实现的归并排序算法详解

//合并两个序列
void mergeArray(int arr[], int first, int mid, int last, int temp[])
{
  int i = first;
  int j = mid + 1;
  int m = mid ;
  int n = last;
  int k = 0;
  while (i <= m && j<=n)
  {
    if (arr[i] <= arr[j])
      temp[k++] = arr[i++];
    else
      temp[k++] = arr[j++];
  }
  while (i <= m)
    temp[k++] = arr[i++];
  while (j <= n)
    temp[k++] = arr[j++];
  for (i = 0; i < k; i++)
    arr[first + i] = temp[i];
}
void mySort(int arr[], int first, int last, int temp[])
{
  if (first < last)
  {
    int mid = (first + last) / 2;
    mySort(arr, first, mid, temp);
    mySort(arr, mid+1, last, temp);
    mergeArray(arr, first, mid, last, temp);
  }
}
bool mergeSort(int arr[], int len)
{
  int*p = new int[len];
  if (NULL == p)
    return false;
  mySort(arr, 0, len - 1, p);
  delete[] p;
  return true;
}

#include <iostream>
using namespace std;
//上述归并排序源码
int main()
{
  int arr[] = { 2, 23, 32, 34, 45, 6, 5, 65, 7, 6, 87, 87, 8, 798, 34, 35, 46, 45, 65, 756, 876, 8, 7, 87, 87, 5, 34, 344, 3, 32 };
  int len = sizeof(arr) / sizeof(int);
  mergeSort(arr, len);
  for (int i = 0; i < len; i++)
    cout << arr[i] << " ";
  cout << endl;
  system("pause");
}

2 3 5 5 6 6 7 7 8 8 23 32 32 34 34 34 35 45 45 46 65 65 87 87 87 87 344 756 798 876
请按任意键继续. . .