C program to perform Npoint DFT

             I would like to write blogs which contains programs in C language or of MATLAB code.The reason is simple,I have a subject called Digital signal processing laboratory.It contains totally 24 programs and in exam we need to write just two,so some programs which I like out of the remaining ones I would like to write them in my blogs.
          C program :
#include<stdio.h>
main();
{
     float y[16],w;
     float  x[4]={1,3,2,5};
     int n,k,k1,N=8,xlen=4;
     for(k=0;k<2*N;k=k+2)
     {
           y[k]=0;
           y[k+1]=0;
            k1=k/2;
            for(n=0;n<xlen;n++)
           {
                 w=-2*3.14*k1*n/N;
                  y[k]=y[k]+x(n)*cos(w);
                  y[k+1]=y[k+1]+x(n)*sin(w);
          }
 }
     printf("%f+j%F",y[k],y[k+1]);
}