我正在尝试制作一个使用第0个索引的heapsort算法，并且适用于整数数组。
我对不同数组的测试表明，使最大堆正常工作的堆的第一部分。排序过程似乎在{33,12,5,85,2,10,11}的前两次运行中交换了正确的数字，但随后又交换了我的最后一个索引。即使代码的类似部分看起来很简单，我似乎也找不到错误。谢谢。
Before: [85, 33, 11, 12, 2, 10, 5]
After: [33, 12, 11, 5, 2, 10, 85]
After: [12, 10, 11, 5, 2, 33, 85]
After: [11, 10, 85, 5, 12, 33, 2]
After: [85, 10, 33, 11, 12, 5, 2]
After: [85, 10, 33, 11, 12, 5, 2]
After: [85, 12, 33, 11, 10, 5, 2]
After: [85, 12, 33, 11, 10, 5, 2]
[85, 12, 33, 11, 10, 5, 2]
package com.example.java;
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
int[] test = {33, 12, 5, 85, 2, 10, 11};
heap mit = new heap(test);
mit.heapsort(test);
System.out.println(Arrays.toString(mit.getPq()));
}
}
package com.example.java;
import java.util.Arrays;
public class heap {
int N = 0;
int[] pq = null;
public heap (int[] n) {
this.pq = new int[n.length];
for (int i = 0; i <n.length ; i++) {
pq[i] = n[i];
N = n.length;
}
}
public boolean less(int i, int j) {
return pq[i] < pq[j];
}
public void exchange(int i, int j) {
int a = pq[i];
pq[i] = pq[j];
pq[j] = a;
}
public int getN() {
return N;
}
public int[] getPq() {
return pq;
}
public void sink(int k) {
while ((2*k)+1 < this.N) {
int j = 2 * k + 1;
if (j+1 < this.N) {
if (less(j, j+1)) j++;
} if (less(k, j)) {
exchange(k, j);
k = j;
} else break;
}
}
public void heapsort(int[] a) {
int N = a.length;
for (int k = N/2; k >=0 ; k--) {
sink(k);
}
System.out.println("Before: " + Arrays.toString(pq));
while (N>0) {
N--;
exchange(0, N);
sink(0);
System.out.println("After: " + Arrays.toString(pq));
}
}
}