Example 1: 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));
}
}
Example 2: quicksort in code
#include <iostream>
using namespace std;
void QuickSort(int arr[], int start, int end);
int Partition(int arr[], int start, int end);
void SwapArrMem(int arr[], int a, int b);
int main()
{
int arr[4];
cout << "enter " << sizeof(arr) / sizeof(arr[0]) << " numbers. press enter after input" << endl;
for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
{
cin >> arr[i];
}
cout << endl << "The sorted numbers are:" << endl << endl;
QuickSort(arr, 0, sizeof(arr) / sizeof(arr[0]) - 1);
for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
{
cout << arr[i] << endl;
}
}
void QuickSort(int arr[], int start, int end)
{
if (start >= end) return;
int index = Partition(arr, start, end);
QuickSort(arr, start, index - 1);
QuickSort(arr, index + 1, end);
}
int Partition(int arr[], int start, int end)
{
int pivotindex = start;
int pivotvalue = arr[end];
for (int i = start; i < end; i++)
{
if (arr[i] < pivotvalue)
{
SwapArrMem(arr, i, pivotindex);
pivotindex++;
}
}
SwapArrMem(arr, pivotindex, end);
return pivotindex;
}
void SwapArrMem(int arr[], int a, int b)
{
int temp = arr[a];
arr[a] = arr[b];
arr[b] = temp;
}