折半插入排序

相比起直接插入排序，折半插入排序减少了关键字的比较次数，而记录的移动次数不变，因此折半插入排序的时间复杂度仍然为O(n^2)

稳定性:稳定

void BInsertSort(int a[], int size) 
{
  int i, j, low = 0, high = 0, mid;
  int temp = 0;
  for (i = 1; i < size; i++) 
  {
    low = 0;
    high = i - 1;
    temp = a[i];
    //采用折半查找法判断插入位置，最终变量 low 表示插入位置
    while (low <= high) 
    {
      mid = (low + high) / 2;
      if (a[mid] > temp) 
      {
        high = mid - 1;
      }
      else {
        low = mid + 1;
      }
    }
    //有序表中插入位置后的元素统一后移
    for (j = i; j > low; j--) {
      a[j] = a[j - 1];
    }
    a[low] = temp;//插入元素
  }
}

完整代码

#include <iostream>
#include <windows.h>
using namespace std;

void PrintArray(int *Array, int iSize)
{
  for (int i = 0; i < iSize; i++)
  {
    cout << "Key is " <<i<<" Current Value is " << Array[i] << endl;
  }
}
void BInsertSort(int a[], int size) 
{
  int i, j, low = 0, high = 0, mid;
  int temp = 0;
  for (i = 1; i < size; i++) 
  {
    low = 0;
    high = i - 1;
    temp = a[i];
    //采用折半查找法判断插入位置，最终变量 low 表示插入位置
    while (low <= high) 
    {
      mid = (low + high) / 2;
      if (a[mid] > temp) 
      {
        high = mid - 1;
      }
      else {
        low = mid + 1;
      }
    }
    //有序表中插入位置后的元素统一后移
    for (j = i; j > low; j--) {
      a[j] = a[j - 1];
    }
    a[low] = temp;//插入元素
  }
}
int main()
{
  int a[10] = { 9,10,8,7,6,5,4,3,2,1 };
  BInsertSort(a,10);

  PrintArray(a,10);
  system("pause");
  return 0;
}