quicksort implementation java code example
Example 1: Quicksort java
import java.util.Arrays;
public class QuickSortInJava
{
int partition(int[] arrNumbers, int low, int high)
{
int pivot = arrNumbers[high];
int a = (low - 1);
for(int b = low; b < high; b++)
{
if(arrNumbers[b] < pivot)
{
a++;
int temp = arrNumbers[a];
arrNumbers[a] = arrNumbers[b];
arrNumbers[b] = temp;
}
}
int temp = arrNumbers[a + 1];
arrNumbers[a + 1] = arrNumbers[high];
arrNumbers[high] = temp;
return a + 1;
}
void sort(int[] arrNumbers, int low, int high)
{
if (low < high)
{
int p = partition(arrNumbers, low, high);
sort(arrNumbers, low, p - 1);
sort(arrNumbers, p + 1, high);
}
}
static void displayArray(int[] arrNumbers)
{
int s = arrNumbers.length;
for(int a = 0; a < s; ++a)
System.out.print(arrNumbers[a] + " ");
System.out.println();
}
public static void main(String[] args)
{
int[] arrNumbers = {59, 74, 85, 67, 56, 29, 68, 34};
int s = arrNumbers.length;
QuickSortInJava obj = new QuickSortInJava();
obj.sort(arrNumbers, 0, s - 1);
System.out.println("After sorting array: ");
displayArray(arrNumbers);
}
}
Example 2: quick sort code in java
import java.util.*;
class QuickSort {
int partition(int intArray[], int low, int high) {
int pi = intArray[high];
int i = (low-1);
for (int j=low; j<high; j++) {
if (intArray[j] <= pi) {
i++;
int temp = intArray[i];
intArray[i] = intArray[j];
intArray[j] = temp;
}
}
int temp = intArray[i+1];
intArray[i+1] = intArray[high];
intArray[high] = temp;
return i+1;
}
void quick_sort(int intArray[], int low, int high) {
if (low < high) {
int pi = partition(intArray, low, high);
quick_sort(intArray, low, pi-1);
quick_sort(intArray, pi+1, high);
}
}
}
class QUICK_SORT{
public static void main(String args[]) {
int intArray[] = {3,2,1,6,5,4};
int n = intArray.length;
System.out.println("Original Array: " + Arrays.toString(intArray));
QuickSort obj = new QuickSort();
obj.quick_sort(intArray, 0, n-1);
System.out.println("\nSorted Array: " + Arrays.toString(intArray));
}
}