Java 已找到:T[],必需:T[]
我已经用通用方法编写了排序算法Quicksort,其中包含参数:Java 已找到:T[],必需:T[],java,algorithm,sorting,generics,Java,Algorithm,Sorting,Generics,我已经用通用方法编写了排序算法Quicksort,其中包含参数: 分区方法:(T[]数组,int-low,int-high) 排序方法:(T[]数组,整数低位,整数高位) 但是,当我尝试在排序方法体中执行递归时,对于数组参数,我得到以下错误: 错误的第一个参数类型。找到:“T[]”,必需:“T[]” 这是排序方法中的代码: if (low < high) { int pi = partition(array, low, high); Quick
- 分区方法:(
)T[]数组,int-low,int-high
- 排序方法:(
)T[]数组,整数低位,整数高位
if (low < high)
{ int pi = partition(array, low, high);
Quicksort(array, low, pi-1);
Quicksort(array, pi+1, high);
}
这里涉及的两种不同的泛型方法都定义了一个类型参数
T
。Quicksort
中的T
没有任何界限,因此它根本不必具有可比性。但是,分区
中的T
需要有一个上界compariable
。编译器错误并没有说明全部原因,但出现错误是因为t
边界不匹配
将T
在Quicksort
中的绑定设置为相同的绑定
static <T extends Comparable<T>> void Quicksort(T[] array, int low, int high)
根据Java编码约定,类(及其构造函数)应该以大写字母开头;方法和变量应以小写字母开头。正因为如此,我想知道为什么您要调用快速排序构造函数两次。
public class DD_ObjectBinarySearcher<T> {
//comparison count for Binary search
static int binarycount = 0;
//comparison count for Sequential search
static int seqcount = 0;
//comparison totals for calculating averages
static int stotal; static int btotal;
/**
*
* @return total counts of Sequential Search
*/
public static int getStotal() {
return stotal;
}
/**
*
* @return total counts of Binary Search
*/
public static int getBtotal() {
return btotal;
}
/**
* @param array array to be sorted
* @param low starting index
* @param high ending index
* @return partition for quick sort
*/
static <T extends Comparable<T>> int partition(T[] array, int low, int high)
{
T pivot = array[high];
int i = (low-1); // index of smaller element
for (int j=low; j<high; j++)
{
if (array[j].compareTo(pivot) <=0)
{
i++;
// swap array[i] and array[j]
T temp = array[i];
array[i] = array[j];
array[j] = temp;
}
}
// swap array[i+1] and array[high] (or pivot)
T temp = array[i+1];
array[i+1] = array[high];
array[high] = temp;
return i+1;
}
/**
* @param array array to be sorted
* @param low starting index
* @param high ending index
*/
static <T> void Quicksort(T[] array, int low, int high)
{
if (low < high)
{ int pi = partition(array, low, high);
Quicksort(array, low, pi-1);
Quicksort(array, pi+1, high);
}
}
/**
* @param a array
* @param b compared integer
* @return flag
*/
static <T extends Comparable<T>> boolean sequentialSearch(T[] a, T b){
for (T i : a) {
if (i==b){
System.out.println("The number of comparisons for unsorted array: " + seqcount);
stotal+=seqcount;
return true;
}
seqcount++;
}
return false;
}
/**
* @param a array
* @param b compared integer
* @return flag
*/
static <T extends Comparable<T>> boolean binarySearch(T[] a, T b) {
if (a.length == 0) return false;
int low = 0;
int high = a.length-1;
while(low <= high ) {
int middle = (low+high) /2;
if (b.compareTo((T) a[middle]) > 0){
low = middle +1;
} else if (b.compareTo((T) a[middle]) < 0){
high = middle -1;
} else { // the element has been found
System.out.println("The number of comparisons for sorted array: " + binarycount);
btotal+=binarycount; //totals are used to calculate average in the main
return true;
}
binarycount++;
}
return false;
}
/**
*
* @param array that will be printed
*/
static void printArray(int[] array)
{
for (int value : array) System.out.print(value + " ");
System.out.println();
}
}
static <T extends Comparable<T>> void Quicksort(T[] array, int low, int high)
static <T extends Comparable<? super T>> void Quicksort(T[] array, int low, int high)
class DD_ObjectBinarySearcher {