Can you provide a code summary for below, please

Please find my code for merge sort to sort an array.

#include

#include

using namespace std;

// Merges two subarrays of arr[].

// First subarray is arr[l..m]

// Second subarray is arr[m+1..r]

void merge(int arr[], int l, int m, int r)

{

int i, j, k;

int n1 = m - l + 1;

int n2 = r - m;

/* create temp arrays */

int L[n1], R[n2];

/* Copy data to temp arrays L[] and R[] */

for (i = 0; i < n1; i++)

L[i] = arr[l + i];

for (j = 0; j < n2; j++)

R[j] = arr[m + 1+ j];

/* Merge the temp arrays back into arr[l..r]*/

i = 0; // Initial index of first subarray

j = 0; // Initial index of second subarray

k = l; // Initial index of merged subarray

while (i < n1 && j < n2)

{

if (L[i] <= R[j])

{

arr[k] = L[i];

i++;

}

else

{

arr[k] = R[j];

j++;

}

k++;

}

/* Copy the remaining elements of L[], if there

are any */

while (i < n1)

{

arr[k] = L[i];

i++;

k++;

}

/* Copy the remaining elements of R[], if there

are any */

while (j < n2)

{

arr[k] = R[j];

j++;

k++;

}

}

/* l is for left index and r is right index of the

sub-array of arr to be sorted */

void mergeSort(int arr[], int l, int r)

{

if (l < r)

{

// Same as (l+r)/2, but avoids overflow for

// large l and h

int m = l+(r-l)/2;

// Sort first and second halves

mergeSort(arr, l, m);

mergeSort(arr, m+1, r);

merge(arr, l, m, r);

}

}

/* UTILITY FUNCTIONS */

/* Function to print an array */

void printArray(int A[], int size)

{

for (int i=0; i < size; i++)

cout<

cout<

}

/* Driver program to test above functions */

int main()

{

int arr[] = {12, 11, 13, 5, 6, 7};

int n = 6;

cout<<"Given array is ";

printArray(arr, n);

mergeSort(arr, 0, n - 1);

cout<<" Sorted array is ";

printArray(arr, n);

return 0;

}