Merge Sort C program for Dev c++

 merges(int a[],int l,int r)  
 {  
  int c=(l+r)/2,i=l;  
  int j=c+1,k=0,x;  
  int b[r-l+1];  
  while(j<=r && i<=c)  
  {  
   if(a[j]<a[i])  
   b[k++]=a[j++];  
   else  
   b[k++]=a[i++];  
   }  
  while(j<=r)  
  b[k++]=a[j++];  
  while(i<=r)  
  b[k++]=a[i++];  
  for(x=l;x<=r;x++)  
  a[x]=b[x-l];  
 }  
 merge_rec(int a[],int l,int r)  
 {  
   int c;  
   if(l<r)  
   {  
    c=(l+r)/2;  
    merge_rec(a,l,c);  
    merge_rec(a,c+1,r);  
    merges(a,l,r);  
   }  
 }  
 int main()  
 {  
   int a[]={1,4,2,11,0,45,9,75,-4,40};  
   int i;  
   merge_rec(a,0,9);  
    for(i=0;i<=9;i++)  
    {  
     printf("%d ",a[i]);  
    }  
    getch();  
 }