Merge Sort Algorithm with C source Codes

Here, I've presented the merge sort algorithm as the straight merge sort. The basic idea is to break the file into n subfiles of size 1 and merge adjacent disjoint pairs of files and repeating the process until we've single file remaining of size n.
 The C Source codes is as follows:

// Merge sort implementation in C

#include<stdio.h>

void getdata(int arr[],int n)
{
 int i;
  printf("\nEnter the data:");
  for(i=0;i<n;i++)
    {
     scanf("%d",&arr[i]);
    }
}

void display(int arr[],int n)
{
 int i;
 printf(" ");
 for(i=0;i<n;i++)
    {
     printf("%d ",arr[i]);
    }
 getchar();
 }

void sort(int arr[],int low,int mid,int high)
{
 int i,j,k,l,b[20];
 l=low;
 i=low;
 j=mid+1;
 while((l<=mid)&&(j<=high))
   {
    if(arr[l]<=arr[j])
      {
       b[i]=arr[l];
       l++;
      }
    else
      {
       b[i]=arr[j];
       j++;
      }
    i++;
   }
 if(l>mid)
  {
    for(k=j;k<=high;k++)
       {
        b[i]=arr[k];
        i++;
       }
   }
 else
   {
    for(k=l;k<=mid;k++)
       {
        b[i]=arr[k];
        i++;
       }
   }
 for(k=low;k<=high;k++)
    {
     arr[k]=b[k];
    }
}

void partition(int arr[],int low,int high)
{
    int mid;
 if(low<high)
   {
    mid=(low+high)/2;
    partition(arr,low,mid);
    partition(arr,mid+1,high);
    sort(arr,low,mid,high);
   }
}


void main()
{
 int arr[20];
 int n;
 printf("Enter number of data:");
 scanf("%d",&n);
 getdata(arr,n);
 partition(arr,0,n-1);
 printf("\nThe Sorted array is :\n");
 display(arr,n);
 getchar();
}