堆排序

#include <stdio.h>#include <string.h>#include <iostream>#include <string>using namespace std;void print(int *a, int n){for (int i = 1; i <= n; i++){printf("%d ", a[i]);}cout << endl;}void heapify(int *a, int x, int n){int l = x << 1;int r = x << 1 | 1;int largest;if (l <= n && a[l] > a[x]){largest = l;}else {largest = x;}if (r <= n && a[r] > a[largest]){largest = r;}if (largest != x){int t = a[largest];a[largest] = a[x];a[x] = t;heapify(a, largest, n);}}void buildHeap(int *a, int n){//在堆中（也就是完全二叉树中），叶子结点的数目应当等于总结点数目（n - n / 2), 所以非叶子结点的数目为n/2（下整） for (int i = n / 2; i >= 1; i--){heapify(a, i, n);}}void heapSort(int *a, int n){buildHeap(a, n);print(a, n);for (int i = n; i > 1; i--){int t = a[i];a[i] = a[1];a[1] = t;heapify(a, 1, i - 1);}}int main(){int n;int a[100];scanf("%d", &n);for (int i = 1; i <= n; i++) //由于创建堆的时候，根结点的编号是从1开始的，所以如果依旧按照从0开始编写序号的话，就不方便 {scanf("%d", &a[i]);}heapSort(a, n);print(a, n);return 0;}