Simpson’s 1/3rd program in c for tabulated values

#include<stdio.h>
#include<conio.h>
#include<math.h>

void main()
{
  int i,n;
  float x[6],y[6],u,k,h=0.05,s,s2,s4,integral;
  clrscr();
  for(i=0;i<7;i++)
  {
     printf("enter x[%d]",i);
     scanf("%f",&x[i]);
     printf("enter y[%d]",i);
     scanf("%f",&y[i]);
  }
  s=y[0]+y[6];
  s2=0;
  s4=0;
  for(i=1;i<=5;i=i+2)
  {
    s4=s4+y[i];
  }
  for(i=2;i<=4;i=i+2)
  {
    s2=s2+y[i];
  }
  integral=(h/3)*(s+2*s2+4*s4);
  printf("integral is %f",integral);
  getch();
}