Implementation of backward interpolation method in C.

Here is the code..

/*BACKWARD INTERPOLATION METHOD*/
#include <stdio.h>

#define m 10
void main()
{
  int n,i,j;
  float mx[m],my[m],x,sum,fun,p,diff[m][m];
  
 printf("Enter the number of terms:\n");
 scanf("%d",&n);
 printf("\n\Enter the %d values of x:\n",n);
 for(i=0;i<n;i++)
  scanf("%f",&mx[i]);
  printf("\n Enter the %d values of y:\n",n);
 for(i=0;i<n;i++)
  scanf("%f",&my[i]);
  printf("\nEnter x for which you want the value of y:\n");
  scanf("%f",&x);
 for(i=0;i<n-1;i++)
  {
   diff[i][1]=my[i+1]-my[i];
  }
 for(j=2;j<n;j++)
   {
    for(i=0;i<n-j;i++)
      {
       diff[i][j]=diff[i+1][j-1]-diff[i][j-1];
}}
 fun=1;
 p=(x-mx[n-1])/(mx[1]-mx[0]);
 sum=my[n-1];
    i=1;
 for(j=1;j<=4;j++)
  {
   i=i*j;
   fun=(fun*(p+(j-1)))/i;
   sum=sum+fun*diff[n-1][j];
   }
 printf("\nwhen x=%6.4f,y=%6.8f",x,sum);
 printf("\n Press Enter to Exit");

}

For Turbo C users.

/*BACKWARD INTERPOLATION METHOD*/
#include <stdio.h>
#include <conio.h>
#define m 10
void main()
{
  int n,i,j;
  float mx[m],my[m],x,sum,fun,p,diff[m][m];
  clrscr();
 printf("Enter the number of terms:\n");
 scanf("%d",&n);
 printf("\n\Enter the %d values of x:\n",n);
 for(i=0;i<n;i++)
  scanf("%f",&mx[i]);
  printf("\n Enter the %d values of y:\n",n);
 for(i=0;i<n;i++)
  scanf("%f",&my[i]);
  printf("\nEnter x for which you want the value of y:\n");
  scanf("%f",&x);
 for(i=0;i<n-1;i++)
  {
   diff[i][1]=my[i+1]-my[i];
  }
 for(j=2;j<n;j++)
   {
    for(i=0;i<n-j;i++)
      {
       diff[i][j]=diff[i+1][j-1]-diff[i][j-1];
}}
 fun=1;
 p=(x-mx[n-1])/(mx[1]-mx[0]);
 sum=my[n-1];
    i=1;
 for(j=1;j<=4;j++)
  {
   i=i*j;
   fun=(fun*(p+(j-1)))/i;
   sum=sum+fun*diff[n-1][j];
   }
 printf("\nwhen x=%6.4f,y=%6.8f",x,sum);
 printf("\n Press Enter to Exit");
 getch();
}