[数据结构]-玩转八大排序（二）&&冒泡排序&&快速排序

//冒泡排序
void BubbleSort(int* a, int n)
{
  int i = 0;
  //控制排序的趟数
  for (i = 0;i < n;i++)
  {
    int exchange = 0;
    //完成一次排序
    for (int j = 0;j < n - 1 - i;j++)
    {
      if (a[j] > a[j + 1])
      {
        swop(&a[j], &a[j + 1]);
        exchange = 1;
      }
      
    }
    //数组有序直接跳出
    if (exchange == 0)
    {
      break;
    }
  }
}

// hoare,区间[left,right]
int PartSort1(int* a, int left, int right)
{
  int keyi = left;
  while (right > left)
  {
    //R找小
    while (right > left && a[right >= a[keyi]])
    {
      --right;
    }
    //L找大
    while (right > left && a[left] <= a[keyi])
    {
      ++left;
    }
    //注意这里R和L交换的前提一定要有right > left
    if (right > left)
    {
      swop(&a[left], &a[right]);
    }
  }
  //出来后R和L相遇,与keyi位置的值交换
  int meeti = left;
  swop(&a[meeti], &a[keyi]);
  return meeti;//返回相遇位置的下标
}

//快速排序
void QuickSort(int* a, int begin,int end)
{
  //递归结束的标志
  if (begin >= end)
    return;
  int keyi = PartSort1(a, begin, end);
  //排key的左区间
  QuickSort(a, begin, keyi - 1);
  //排key的右区间
  QuickSort(a, keyi+1,end);
}

//挖坑法
int  PartSort2(int* a, int left, int right)
{
  int hole = left;
  int key = a[left];
  while (left < right)
  {
    //R找小数，填到左边坑中
    while (left < right && a[right] >= key)
    {
      --right;
    }
    a[hole] = a[right];
    hole = right;//形成新的右边坑位
    //L找到数。填到右边坑位中
    while (left < right && a[left] <= key)
    {
      ++left;
    }
    a[hole] = a[left];
    hole = left;//形成新的左边坑位
  }
  a[hole] = key;
  return hole;
}

//前后指针法
int PartSort3(int* a, int left, int right)
{
  int prev = left;
  int cur = left + 1;
  int keyi = left;
  while (cur <= right)
  {
    //找小
    if (a[cur] < a[keyi] && ++prev != cur)
      swop(&a[cur], &a[prev]);
    ++cur;
  }
  //cur越界，交换
  swop(&a[keyi], &a[prev]);
  return prev;
}

//测试性能
void TestOP()
{
  srand(time(0));
  const int N = 100000;
  int* a1 = (int*)malloc(sizeof(int) * N);
  int* a2 = (int*)malloc(sizeof(int) * N);
  int* a3 = (int*)malloc(sizeof(int) * N);
  int* a4 = (int*)malloc(sizeof(int) * N);
  int* a5 = (int*)malloc(sizeof(int) * N);
  int* a6 = (int*)malloc(sizeof(int) * N);
  for (int i = 0; i < N; ++i)
  {
    a1[i] = rand();
    a2[i] = a1[i];
    a3[i] = a1[i];
    a4[i] = a1[i];
    a5[i] = a1[i];
    a6[i] = a1[i];
 
  }
  int begin1 = clock();
  InsertSort(a1, N);
  int end1 = clock();
  int begin2 = clock();
  ShellSort(a2, N);
  int end2 = clock();
  int begin3 = clock();
  SelectSort(a3, N);
  int end3 = clock();
  int begin4 = clock();
  HeapSort(a4, N);
  int end4 = clock();
  int begin5 = clock();
  QuickSort(a5, 0, N - 1);
  int end5 = clock();
  int begin6 = clock();
  //MergeSort(a6, N);
  int end6 = clock();
  printf("InsertSort:%d\n", end1 - begin1);
  printf("ShellSort:%d\n", end2 - begin2);
  printf("SelectSort:%d\n", end3 - begin3);
  printf("HeapSort:%d\n", end4 - begin4);
  printf("QuickSort:%d\n", end5 - begin5);
  printf("MergeSort:%d\n", end6 - begin6);
  free(a1);
  free(a2);
  free(a3);
  free(a4);
  free(a5);
  free(a6);
}
 
int main()
{
  //int a[] = { 9,3,4,1,8,0 };
  //int n = sizeof(a) / sizeof(a[0]);
  TestOP();
  //testheap();
  /*BubbleTest(a, n);*/
  //QuickTest(a, n);
  return 0;
}

//三数取中
int GetMidIndex(int* a, int left,int right)
{
  int mid = (left + right) / 2;
  //三数二二比较
  if (a[left] < a[mid])
  {
    if (a[mid] < a[right])
    {
      return mid;
    }
    else if (a[mid] > a[left])
    {
      return right;
    }
    else
    {
      return left;
    }
  }
  else//(a[left] > a[mid]
  {
    if (a[mid] > a[right])
    {
      return mid;
    }
    else if (a[right] > a[left])
    {
      return left;
    }
    else
    {
      return right;
    }
  }
}

//快速排序
void QuickSort(int* a, int begin,int end)
{
  //递归结束的标志
  if (begin >= end)
    return;
  //最后3层改为插入排序
  if (end - begin < 8)
  {
    InsertSort(a + begin, end - begin - 1);
  }
  else
  {
    int keyi = PartSort3(a, begin, end);
    //排key的左区间
    QuickSort(a, begin, keyi - 1);
    //排key的右区间
    QuickSort(a, keyi + 1, end);
  }
}

//非递归实现
void QuickSortNonR(int* a, int begin, int end)
{
  ST st;
  StackInit(&st);
  //数组区间入栈
  StackPush(&st, begin);
  StackPush(&st, end);
  while (!StackEmpty(&st))
  {
    //出区间
    int right = StackTop(&st);
    StackPop(&st);
    int left = StackTop(&st);
    StackPop(&st);
    //单趟排序
    int keyi = PartSort3(a, left, right);
    //如果区间中的元素>1
    //先入右边的区间
    if (right > keyi + 1)
    {
      StackPush(&st, keyi+1);
      StackPush(&st, end);
    }
    //在入左边区间
    if (left < keyi - 1)
    {
      StackPush(&st, left);
      StackPush(&st, keyi-1);
    }
  }
  //销毁栈
  StackDestroy(&st);
}