Reverse an array in groups of given size

// C++ program to reverse every sub-array formed by
// consecutive k elements
#include <iostream>
using namespace std;

// Function to reverse every sub-array formed by
// consecutive k elements
void reverse(int arr[], int n, int k)
{
	for (int i = 0; i < n; i += k)
	{
		int left = i;

		// to handle case when k is not multiple of n
		int right = min(i + k - 1, n - 1);

		// reverse the sub-array [left, right]
		while (left < right)
			swap(arr[left++], arr[right--]);

	}
}

// Driver code
int main()
{
	int arr[] = {1, 2, 3, 4, 5, 6, 7, 8};
	int k = 3;

	int n = sizeof(arr) / sizeof(arr[0]);

	reverse(arr, n, k);

	for (int i = 0; i < n; i++)
		cout << arr[i] << " ";

	return 0;
}