quick.cpp

#include <bits/stdc++.h>
using namespace std;  
void swap(int* a, int* b)  
{  
    int t = *a;  
    *a = *b;  
    *b = t;  
}  
int partition (int arr[], int low, int high)  
{  
    int pivot = arr[high];  
    int i = (low - 1);  
  
    for (int j = low; j <= high - 1; j++)  
    {  
          
        if (arr[j] < pivot)  
        {  
            i++;   
            swap(&arr[i], &arr[j]);  
        }  
    }  
    swap(&arr[i + 1], &arr[high]);  
    return (i + 1);  
}  
  
void quickSort(int arr[], int low, int high)  
{  
    if (low < high)  
    {  
        int pi = partition(arr, low, high);  
  
        quickSort(arr, low, pi - 1);  
        quickSort(arr, pi + 1, high);  
    }  
}  
  
void printArray(int arr[], int size)  
{  
    int i;  
    for (i = 0; i < size; i++)  
        cout << arr[i] << " ";  
    cout << endl;  
}  
  
int main()  
{  
    //int arr[] = {10, 7, 8, 9, 1, 5}; 
	int n1;
	cout<<"enter length of array";
	cin>>n1;
	cout<<"enter elements"<<endl;
	int arr[n1];
	for(int i=0;i<n1;i++)
	{
		cin>>arr[i];
	} 
    int n = sizeof(arr) / sizeof(arr[0]);  
    quickSort(arr, 0, n - 1);  
    cout << "Sorted array: \n";  
    printArray(arr, n);  
    return 0;  
}