我目前正在研究一种基本的冒泡排序方式，但它使用Comparable，并且由于无法确定在何处实现其功能而将我赶走了。
这就是我所得到的，无法改变public static <T extends Comparable<? super T>> void bubbleSort_Itr(T[] arr) {
if(arr == null) throw new NullPointerException(); if(arr.length == 0) throw new IllegalArgumentException(); if(arr.length == 1) return;
}
这是我在测试课程中创建的
public class HubbaBubbaSort {
public static <T extends Comparable<? super T>> void bubbleSort_Itr(T[] arr)
{
if(arr == null) throw new NullPointerException();
if(arr.length == 0) throw new IllegalArgumentException();
if(arr.length == 1) return;
int n = arr.length;
for (int i = 0; i < n-1; i++)
for (int j = 0; j < n-i-1; j++)
if (arr[j] > arr[j+1])
{
// swap T temp and arr[i]
T temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
/* Prints the array */
void printArray(int arr[])
{
int n = arr.length;
for (int i=0; i<n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver method to test above
public static void main(String args[])
{
HubbaBubbaSort ob = new HubbaBubbaSort();
int arr[] = {64, 34, 25, 12, 22, 11, 90};
ob.bubbleSort_Itr(arr);
System.out.println("Sorted array");
ob.printArray(arr);
}
}
最佳答案
这里的关键是Comparable接口：
https://docs.oracle.com/javase/8/docs/api/java/lang/Comparable.html
int compareTo(T o)
Parameters:
o - the object to be compared.
Returns:
a negative integer, zero, or a positive integer as this object is less than,
equal to, or greater than the specified object.
一旦我们知道如何比较对象，就可以使用它来执行气泡排序。另外，由于int是原始类型，并且无法实现Comparable，因此我将其切换为Integers。
public class HubbaBubbaSort {
public static <T extends Comparable<? super T>> void bubbleSort_Itr(T[] arr) {
if (arr == null)
throw new NullPointerException();
if (arr.length == 0)
throw new IllegalArgumentException();
if (arr.length == 1)
return;
int n = arr.length;
for (int i = 0; i < n - 1; i++)
for (int j = 0; j < n - i - 1; j++)
if (arr[j].compareTo(arr[j + 1])>0) {
// swap T temp and arr[i]
T temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
/* Prints the array */
void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver method to test above
public static void main(String args[]) {
HubbaBubbaSort ob = new HubbaBubbaSort();
Integer arr[] = { 64, 34, 25, 12, 22, 11, 90 };
ob.bubbleSort_Itr(arr);
System.out.println("Sorted array");
System.out.println(Arrays.toString(arr));
}
}