排序算法 堆排序

堆排序使用最大堆。堆排序：将初始序列构造成最大堆； 第一趟排序，将堆顶元素 A[0] 和堆底元素 A[n-1]进行交换，然后调用AdjustDown对堆顶元素进行向下调整，使剩余的前n-1个元素还是堆。然后使堆顶元素与A[n-2]交换，在进行向下调整。直到最后只剩下堆顶元素。

template <class T>void AdjustDown(T heap[],int r,int j){T temp = heap[r];int child = 2 * r + 1;while(child < j ){child = heap[child] < heap[child+1] ? (child+1) : child;if(temp < heap[child]){heap[r] = heap[child];heap[child] = temp;r = child ;child = 2 * r + 1;temp = heap[r];}elsebreak;}}template <class T>void CreateHeap(T heap[],int n){for(int i = n/2 - 1;i>-1;i--)AdjustDown(heap,i,n-1);}template <class T>void swap(T &a, T &b){T temp = a;a = b;b = temp;}template <class T>void HeapSort(T A[],int n){CreateHeap(A,n);for(int i = n-1 ;i > 0 ; i--){swap(A[0],A[i]);AdjustDown(A,0,i-1);}}int main(){int A[7] = {99,36,68,72,12,48,02};HeapSort(A,7);return 0;}