added the quicksort implementation in c++

quicksort.cpp

@@ -0,0 +1,87 @@
+#include<iostream>
+#include<cstdlib>
+
+using namespace std;
+
+// Swapping the two values
+void swap(int *a, int *b)
+{
+	int temp; 
+	temp = *a;
+	*a = *b;
+	*b = temp;
+}
+
+// Partitioning the array on the basis of values at high as pivot value.
+int Partition(int a[], int low, int high)
+{
+	int pivot, index, i;
+	index = low;
+	pivot = high;
+
+	// Getting index of pivot.
+	for(i=low; i < high; i++)
+	{
+		if(a[i] < a[pivot])
+		{
+			swap(&a[i], &a[index]);
+			index++;
+		}
+	}
+	// Swapping value at high and at the index obtained.
+	swap(&a[pivot], &a[index]);
+
+	return index;
+}
+
+// Random selection of pivot.
+int RandomPivotPartition(int a[], int low, int high)
+{
+	int pvt, n, temp;
+	n = rand();
+	// Randomizing the pivot value in the given subpart of array.
+	pvt = low + n%(high-low+1);
+
+	// Swapping pvt value from high, so pvt value will be taken as pivot while partitioning.
+	swap(&a[high], &a[pvt]);
+
+	return Partition(a, low, high);
+}
+
+// Implementing QuickSort algorithm.
+int QuickSort(int a[], int low, int high)
+{
+	int pindex;
+	if(low < high)
+	{
+		// Partitioning array using randomized pivot.
+		pindex = RandomPivotPartition(a, low, high);
+		// Recursively implementing QuickSort.
+		QuickSort(a, low, pindex-1);
+		QuickSort(a, pindex+1, high);
+	}
+	return 0;
+}
+
+int main()
+{
+	int n, i;
+	cout<<"\nEnter the number of data element to be sorted: ";
+	cin>>n;
+
+	int arr[n];
+	for(i = 0; i < n; i++)
+	{
+		cout<<"Enter element "<<i+1<<": ";
+		cin>>arr[i];
+	}
+
+	QuickSort(arr, 0, n-1);
+
+	// Printing the sorted data.
+	cout<<"\nSorted Data ";
+	for (i = 0; i < n; i++)
+        	cout<<"->"<<arr[i];
+
+	return 0;
+}