堆排序算法的实现！！

#include <cstdio> #include <cstring> #include <algorithm> using namespace std; #define parent(i) (i)/2 #define left(i) 2*(i) #define right(i) 2*(i)+1 int size; void heapify(int a[], int i) { int l = left(i), r = right(i), largest; if(l<=size && a[l] > a[i]) largest = l; else largest = i; if(r<=size && a[r] > a[largest]) largest = r; if(largest != i) { int t = a[i]; a[i] = a[largest]; a[largest] = t; heapify(a, largest); } } void build_heap(int a[]) { int len = size; for(int i=len/2; i>=1; i--) heapify(a, i); } void heap_sort(int a[]) { build_heap(a); for(int i=size; i>=2; i--) { int t = a[1]; a[1] = a[i]; a[i] = t; size--; heapify(a, 1); } } int main() { int a[20]; printf("请输入数据个数： "); scanf("%d", &size); int len = size; printf("请输入%d个你要排序的数： ", size); for(int i=1; i<=size; i++) scanf("%d", &a[i]); heap_sort(a); for(int i=1; i<len; i++) printf("%d ", a[i]); printf("%d ", a[len]); return 0; }