Java 修改以允许对包含重复元素的数组进行快速排序
我下面的代码适用于具有不同数字的数组,但对于包含重复项的数组则失败。如何修改下面的代码,使其即使在包含重复项的数组中也能工作Java 修改以允许对包含重复元素的数组进行快速排序,java,quicksort,Java,Quicksort,我下面的代码适用于具有不同数字的数组,但对于包含重复项的数组则失败。如何修改下面的代码,使其即使在包含重复项的数组中也能工作 import java.util.Random; public class QuickSortNew { public static void main(String[] args) { // int[] a = {1,4,10,3,8,7,5,2,6,9}; // int[] a = {1,49,30,15,27,21,1,20,1,39}
import java.util.Random;
public class QuickSortNew {
public static void main(String[] args) {
// int[] a = {1,4,10,3,8,7,5,2,6,9};
// int[] a = {1,49,30,15,27,21,1,20,1,39};
// int[] a = {33, 47, 4, 9, 27, 16, 3, 10, 4, 43};
// int[] a = {3, 1, 4, 1, 10, 9, 74, 16, 99, 27, 31, 43, 28, 33, 47};
int[] a = {3, 4, 4};
// int[] a = new int[10];
// populate(a);
// print(a);
// System.out.println("");
fun(a, 0, a.length-1);
print(a);
}
static void fun(int[] a, int l, int h)
{
if(l >= h)
return;
int pivot = a[(l+h)/2];
int startl = l;
int starth = h;
while(l < h)
{
while(a[l] < pivot)
l++;
while(a[h] > pivot)
h--;
if(l < h)
{
int t = a[l];
a[l] = a[h];
a[h] = t;
}
}
fun(a, startl, l-1);
fun(a, l+1, starth);
}
static void populate(int[] a)
{
Random rand = new Random();
for(int i = 0;i<10;i++)
a[i] = rand.nextInt(50);
}
static void print(int[] a)
{
for(int i = 0 ;i<a.length;i++)
System.out.print(a[i] + " ");
}
}
import java.util.Random;
公共类QuickSortNew{
公共静态void main(字符串[]args){
//int[]a={1,4,10,3,8,7,5,2,6,9};
//int[]a={1,49,30,15,27,21,1,20,1,39};
//int[]a={33,47,4,9,27,16,3,10,4,43};
//int[]a={3,1,4,1,10,9,74,16,99,27,31,43,28,33,47};
int[]a={3,4,4};
//int[]a=新的int[10];
//(a);
//印刷品(a);
//System.out.println(“”);
乐趣(a,0,a.length-1);
印刷品(a);
}
静态虚空乐趣(int[]a,int l,int h)
{
如果(l>=h)
返回;
int-pivot=a[(l+h)/2];
int START=l;
int starth=h;
而(l枢轴)
h--;
if(lwhile(数组[i]如何while(数组[i]
private void quickSort(int lowerIndex, int higherIndex) {
int i = lowerIndex;
int j = higherIndex;
// calculate pivot number, I am taking pivot as middle index number
int pivot = array[lowerIndex+(higherIndex-lowerIndex)/2];
// Divide into two arrays
while (i <= j) {
/**
* In each iteration, we will identify a number from left side which
* is greater then the pivot value, and also we will identify a number
* from right side which is less then the pivot value. Once the search
* is done, then we exchange both numbers.
*/
while (array[i] < pivot) {
i++;
}
while (array[j] > pivot) {
j--;
}
if (i <= j) {
System.out.println("i=="+i+",j=="+j+",entering inside the condition...");
exchangeNumbers(i, j);
//move index to next position on both sides
i++;
j--;
}
}
// call quickSort() method recursively
if (lowerIndex < j)
quickSort(lowerIndex, j);
if (i < higherIndex)
quickSort(i, higherIndex);
}
private void exchangeNumbers(int i, int j) {
int temp = array[i];
array[i] = array[j];
array[j] = temp;
}
import java.util.Arrays;
import java.util.Random;
public class QuickSortNew {
public static void main(String[] args) {
// int[] a = {1,4,10,3,8,7,5,2,6,9};
// int[] a = {1,49,30,15,27,21,1,20,1,39};
// int[] a = {33, 47, 4, 9, 27, 16, 3, 10, 4, 43};
// int[] a = {3, 1, 4, 1, 10, 9, 74, 16, 99, 27, 31, 43, 28, 33, 47};
// int[] a = {3, 4, 4};
// int[] a = {1,2,7,6,10,11,4,12,13,5,14,15,8,3,9};
// int[] a = {1,7,6,10,11,4,12,13};
// int[] a = {3, 1, 4, 1, 10, 9, 74, 16, 99};
Random rand = new Random();
int n = rand.nextInt(50)+1;
int[] a = new int[n];
int[] b = new int[n];
populate(n,a);
for(int i = 0;i<a.length;i++)
b[i] = a[i];
System.out.print("Original array : ");
print(b);
System.out.println("");
fun(a, 0, a.length-1);
System.out.print("My sort : ");
print(a);
Arrays.sort(b);
System.out.println("");
System.out.print("Library sort: ");
print(b);
System.out.println("");
System.out.println("Is my sort equal to library sort ? "+Arrays.equals(a, b));
}
static void fun(int[] a, int l, int h)
{
if(l >= h)
return;
int pivot = a[(l+h)/2];
int pivotpos = (l+h)/2;
int startl = l;
int starth = h;
while(l < h)
{
while(a[l] <= pivot && pivotpos!=l )
l++;
while(a[h] >= pivot && pivotpos!=h )
h--;
if(l < h)
{
int t = a[l];
a[l] = a[h];
a[h] = t;
if(l==pivotpos)
pivotpos = h;
else if(h == pivotpos)
pivotpos = l;
}
}
fun(a, startl, l-1);
fun(a, l+1, starth);
}
static void populate(int n, int[] a)
{
Random rand = new Random();
for(int i = 0;i<n;i++)
a[i] = rand.nextInt(50);
}
static void print(int[] a)
{
for(int i = 0 ;i<a.length;i++)
System.out.print(a[i] + " ");
}
}