我已经编写了这段代码,但它会在控制台中打印这些堆栈跟踪,请帮助我,谢谢!(“p”和“q”分别是我们数组的第一个和最后一个索引)
public class JavaQuickSort {
public static void QuickSort(int A[], int p, int q) {
int i, last = 0;
Random rand = new Random();
if (q < 1) {
return;
}
**swap(A, p, rand.nextInt() % (q+1));**
for (i = p + 1; i <= q; i++) {
if (A[i] < A[p]) {
swap(A, ++last, i);
}
}
swap(A, p, last);
QuickSort(A, p, last - 1);
QuickSort(A, last + 1, q);
}
private static void swap(int[] A, int i, int j) {
int temp;
temp = A[i];
**A[i] = A[j];**
A[j] = temp;
}
public static void main(String[] args){
int[] A = {2,5,7,3,9,0,1,6,8};
**QuickSort(A, 0,8 );**
System.out.println(Arrays.toString(A));
}
}
堆栈跟踪:
run:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -3
at JavaQuickSort.swap(JavaQuickSort.java:38)
at JavaQuickSort.QuickSort(JavaQuickSort.java:22)
at JavaQuickSort.main(JavaQuickSort.java:45)
Java Result: 1
BUILD SUCCESSFUL (total time: 2 seconds)
我还将导致这些堆栈跟踪的那些语句加粗。喜欢 ==> ** ...**
编辑:
public class JavaQuickSort {
public static void QuickSort(int arr[],int lo,int hi) {
int n = arr.length;
if(n<=1)
return;
**int r = partition(arr);**
**QuickSort(arr,lo , r-1);**
QuickSort(arr, r+1, hi);
}
private static void swap(int[] A, int i, int j) {
int temp;
temp = A[i];
**A[i] = A[j];**
A[j] = temp;
}
public static int partition(int arr[]){
int i, last = 0;
Random rand = new Random();
int n = arr.length;
if (n <= 1)
return arr[0];
**swap(arr, 0, rand.nextInt(n));**
for (i =1; i <n; i++) {
if (arr[i] < arr[0]) {
swap(arr, ++last, i);
}
}
swap(arr, 0, last);
return last;
}
public static void main(String[] args){
int[] A = {2,5,7,3,9,0,1,6,8};
**QuickSort(A, 0,8 );**
System.out.println(Arrays.toString(A));
}
}
为了更容易理解,我编辑了我的帖子,它还将打印这些堆栈跟踪,并且我将导致这些堆栈跟踪的行加粗!!!
堆栈跟踪:
run:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
at JavaQuickSort.swap(JavaQuickSort.java:27)
at JavaQuickSort.partition(JavaQuickSort.java:39)
at JavaQuickSort.QuickSort(JavaQuickSort.java:19)
at JavaQuickSort.QuickSort(JavaQuickSort.java:20)
at JavaQuickSort.QuickSort(JavaQuickSort.java:20)
at JavaQuickSort.QuickSort(JavaQuickSort.java:20)
at JavaQuickSort.QuickSort(JavaQuickSort.java:20)
at JavaQuickSort.main(JavaQuickSort.java:52)
Java Result: 1
BUILD SUCCESSFUL (total time: 2 seconds)
请帮帮我谢谢
编辑:
我已经写了这段代码,注意这篇文章的第一答案,但它不会对我的数组进行排序!!!
public class JavaQuickSort {
public static void QuickSort(int arr[], int lo, int hi) {
if (hi > lo) {
Random rand = new Random();
int pivotIndex = lo + rand.nextInt(hi-lo+1);
int pivotnewIndex = partition(arr, lo, hi,pivotIndex);
QuickSort(arr, lo, pivotnewIndex - 1);
QuickSort(arr, pivotnewIndex + 1, hi);
}
}
private static void swap(int[] A, int i, int j) {
int temp;
temp = A[i];
A[i] = A[j];
A[j] = temp;
}
public static int partition(int arr[],int lo,int hi,int pivotIndex)
{
int pivotValue = arr[pivotIndex];
swap(arr, hi, pivotIndex);
int storeIndex = lo;
for(int i = lo;i<hi;i++){
if (arr[i]<=pivotValue)
swap(arr, storeIndex, i);
storeIndex = storeIndex ++;
}
swap(arr, storeIndex, hi);
return storeIndex;
}
public static void main(String[] args) {
int[] A = {2, 5, 7, 3, 9, 0, 1, 6, 8};
QuickSort(A, 0, 8);
System.out.println(Arrays.toString(A));
}
}
输出:
run:
[2, 9, 3, 8, 0, 6, 7, 1, 5]
BUILD SUCCESSFUL (total time: 2 seconds)
我需要你的帮助我真的很困惑!