Merge Sort

The following is the implementation of Merge Sort in terms of a C program. If you have any doubts or corrections, please let me know.

#include<stdio.h>

void mergesort(int x[20],int n)

  {

     int temp[20],i,j,k,l1,l2,size,u1,u2,a;

     size=1;

     while(size<n)

        {

           l1=0;

           k=0;

           while(l1+size<n)

             {

               l2=l1+size;

               u1=l2-1;

               u2=((l2+size-1<n)?l2+size-1:n-1);

               for(i=l1,j=l2;i<=u1&&j<=u2;k++)

                  {

                    if(x[i]<=x[j])

                      {

                         temp[k]=x[i];

                         i++;

                      }

                    else

                      {

                         temp[k]=x[j];

                         j++;

                      }

                   }

               for(;i<=u1;k++)

                   {

                      temp[k]=x[i];

                      i++;

                   }

               for(;j<=u2;k++)

                   {

                      temp[k]=x[j];

                      j++;

                   }

                l1=u2+1;

             }

      for(i=l1;k<n;k++)

        temp[k++]=x[i];

      for(i=0;i<n;i++)

         x[i]=temp[i];

      size=size*2;

      for(a=0;a<n;a++)

          printf(" %d  ",x[a]);

       printf("\n");

   }

}

main()

  {

    int x[20],n,i;

    printf("\nEnter the size:");

    scanf("%d",&n);

    printf("\nEnter the values");

    for(i=0;i<n;i++)

      scanf("%d",&x[i]);

    mergesort(x,n);

   }