is merge Sort the best sorting algorithm code example

Example 1: merge sort vs quicksort

Efficiency :

Merge sort is more efficient and works faster than quick sort in case of larger array size or datasets.
whereas
Quick sort is more efficient and works faster than merge sort in case of smaller array size or datasets.
Preferred for :

Quick sort is preferred for arrays.
whereas
Merge sort is preferred for linked lists.

Example 2: merge sort algorithm

/*  
    a[] is the array, p is starting index, that is 0, 
    and r is the last index of array. 
*/

#include 

// lets take a[5] = {32, 45, 67, 2, 7} as the array to be sorted.

// merge sort function
void mergeSort(int a[], int p, int r)
{
    int q;
    if(p < r)
    {
        q = (p + r) / 2;
        mergeSort(a, p, q);
        mergeSort(a, q+1, r);
        merge(a, p, q, r);
    }
}

// function to merge the subarrays
void merge(int a[], int p, int q, int r)
{
    int b[5];   //same size of a[]
    int i, j, k;
    k = 0;
    i = p;
    j = q + 1;
    while(i <= q && j <= r)
    {
        if(a[i] < a[j])
        {
            b[k++] = a[i++];    // same as b[k]=a[i]; k++; i++;
        }
        else
        {
            b[k++] = a[j++];
        }
    }
  
    while(i <= q)
    {
        b[k++] = a[i++];
    }
  
    while(j <= r)
    {
        b[k++] = a[j++];
    }
  
    for(i=r; i >= p; i--)
    {
        a[i] = b[--k];  // copying back the sorted list to a[]
    } 
}

// function to print the array
void printArray(int a[], int size)
{
    int i;
    for (i=0; i < size; i++)
    {
        printf("%d ", a[i]);
    }
    printf("\n");
}
 
int main()
{
    int arr[] = {32, 45, 67, 2, 7};
    int len = sizeof(arr)/sizeof(arr[0]);
 
    printf("Given array: \n");
    printArray(arr, len);
    
    // calling merge sort
    mergeSort(arr, 0, len - 1);
 
    printf("\nSorted array: \n");
    printArray(arr, len);
    return 0;
}