羣裏一位老大貼的排序算法

這是我QQ羣裏一個老大的貼的排序算法,感覺比較經典,所以就貼到這了.

 

void swap(int *a, int *b)
{
  int t=*a; *a=*b; *b=t;
}
void sort(int arr[], int beg, int end)
{
  if (end > beg + 1)
  {
    int piv = arr[beg], l = beg + 1, r = end;
    while (l < r)
    {
      if (arr[l] <= piv)
        l++;
      else
        swap(&arr[l], &arr[--r]);
    }
    swap(&arr[--l], &arr[beg]);
    sort(arr, beg, l);
    sort(arr, r, end);
  }
}
void sort2(int arr[], int size)
{
 int i = 0;
 int j = 0;
 while(i<size)
 {
  if(arr[i] < arr[j])
  {
   swap(&arr[i], &arr[j]);
   i-=2;
  }
  j = i;
  if(j<0)
   j = 0;
  i++;
 }
}

 

int heapSize = 10;
void print(int a[]) {
  for (int i = 0; i <= 9; i++) {
    cout << a[i] << "-";
  }
  cout << endl;
}

int parent(int i) {
if(i==1)
return 0;

if(i%2==0)
    return ( (i / 2)-1);
else
    return ( (i / 2));
}

int left(int i) {
  return (2 * i) + 1;
}

int right(int i) {
  return (2 * i) + 2;
}

void heapify(int a[], int i) {
  int l = left(i), great;
  int r = right(i);
  if ( (a[l] > a[i]) && (l < heapSize)) {
    great = l;
  }
  else {
    great = i;
  }
  if ( (a[r] > a[great]) && (r < heapSize)) {
    great = r;
  }
  if (great != i) {
    int temp = a[i];
    a[i] = a[great];
    a[great] = temp;
    heapify(a, great);
  }
}

void BuildMaxHeap(int a[]) {
  for (int i = (heapSize - 1) / 2; i >= 0; i--) {
    heapify(a, i);
    print(a);
  }
}

void HeapSort(int a[]) {
  BuildMaxHeap(a);
  for (int i = heapSize; i > 0; i--) {
    int temp = a[0];
    a[0] = a[heapSize - 1];
    a[heapSize - 1] = temp;
    heapSize = heapSize - 1;
    heapify(a, 0);
  }

}