Finding primitive polynomials

This code should find primitive polynomials[cannot be factored in a field where their coefficients are 0 and 1]. The problem is the first and the last degree are shown but the middle coefficients are coming to 0. I am not able figure out the problem properly. The same logic worked in C using unsigned longs.

import java.util.*;

public class Poly {
	public static final int MAX = 32;
	public static final long ONE = 1;
	public static final long TWO = 2;

/* globals */
	private int n;              /* degree of the polynomial */
	private long twonm1;        /* 2^n-1 */
	private long checked = 0;   /* number checked so far */
	private long printed = 0;   /* number printed so far */
	private boolean doneFlag;      /* for early exit */

/* run paramaters */
	private int type;
	private int outformat;
	private long maxNumber;
	private int printOrder;

/* stats */
	private long ir_count = 0;
	private long pr_count = 0;
	private long prim_poly;

/* the necklace */
	public static int[] b = new int[MAX + 1];

private int[] poly_table  = {1,1,3,3,3,5,3,3,29,17,9,5,83,27,43,3,45,9,39,39,9,5,3,33,27,9,71,39,9,5,83,9};
	public Poly() {
		this.outformat = 0;
		this.type = 1;
		this.maxNumber = 0;
    	this.printOrder = 1;
	}
	public void display() {
		System.out.printf( "\n\ndegree      = %d\n", n );
		System.out.printf( "format      = %d\n", outformat );
		System.out.printf( "type        = %s\n", (type == 1)? "primitive" : "all" );
		System.out.printf( "num         = %d %s\n", maxNumber, (maxNumber == 1)? "" : "(none)" );
    	System.out.printf( "ord         = %d %s\n", printOrder, (printOrder == 1) ? "(yes)" : "(no)"  );
	}

/* for checking primitivity */
	long gcd ( long n, long m ) {
	  if (m == 0) return(n);
	  else return( gcd( m, n%m ) );
	}
	
	void PrintBitString( int n, long a ) {
	  int i;
	  System.out.printf("1");
	  for ( i=n-1; i>0; i-- )
	    if ( (a & (ONE<<i)) == 1 ) System.out.printf("1");
	    else System.out.printf("0");
	  System.out.printf("1\n");
	}

void PrintPoly( int n, long a ) {
	  int i;
	  System.out.printf("x^%d + ", n );
	  for ( i=n-1; i>0; i-- )
	    if ( (a & (ONE<<i)) == 1 ) {
	      if (i != 1) System.out.printf("x^%d + ", i );
	      else System.out.printf( "x + " );
	    }
	  System.out.printf("1\n");
	}

void PrintCoefString( int n, long a ) {
	  int i;
	  System.out.printf( "%d\0", n );
	  for ( i=n-1; i>0; i-- )
	    if ( (a & (ONE<<i)) == 1 ) System.out.printf( ", %d\0", i );
	  System.out.printf(", 0\n");
	}

long computeReverse ( int n, long a ) {
	  int i;
	  long a_rev = 1;
	  for ( i=n-1; i>0; i-- )
	     if ( (a & (ONE<<i)) == 1 ) a_rev |= (ONE << (n-i));
	  return a_rev;
	}

long multmod( int n, long a, long b, long p ) {
	  long t, rslt;
	  long top_bit;
	  int i;

rslt = 0;
	  t = a; /* t is a*x^i */
	  top_bit = ONE << (n-1);

for ( i=0; i<n; i++ ) {
	     if ((b & ONE) == 1) rslt ^= t;
	     if ((t & top_bit) == 1)
	        t = ( (t & ~top_bit) << 1 ) ^ p;
	     else
	        t = t << 1;
	     b = b >> 1;
	  }
	  return rslt;
	}

long powmod( int n, long a, long power, long p ) {
	  long t = a;
	  long rslt = ONE;
	  while ( power != 0 ) {
	    if ( (power & ONE) == 1) rslt = multmod( n, t, rslt, p );
	    t = multmod( n, t, t, p );
	    power = power >> 1;
	  }
	  return rslt;
	}

long minpoly( int n, long necklace, long p ) {
	  long root, rslt = 0;
	  long[] f = new long[MAX];
	  int i, j;

f[0] = ONE;
	  for (i=1; i<n; i++ ) f[i] = 0;

root = powmod( n, TWO, necklace, p ); /* '2' is monomial x */
	  for (i=1; i<=n; i++ ) {
	    if (i != 1)
	      root = multmod( n, root, root, p );

for (j=n-1; j>=1; j--)
	      f[j] = f[j-1] ^ multmod( n, f[j], root, p );
	    f[0] = multmod( n, f[j], root, p );
	  }

for (i=0; i<n; i++ )
	    if (f[i] == ONE)
	      rslt |= ONE << i;
	    else if (f[i] != 0)
	    	System.out.println("Ahh!");

return rslt;
	}

long toInt ( ) {
		long x;
		int i;
	  	x = 0;
	  	for (i=1; i<=n; ++i) {
	     	x = TWO*x;
	     	if (b[i] == 1) ++x;
	  	}
	  	return x;
	}

void OutputPolys( int n, long m, long gcdResult ) {
	    //if (printOrder == 1) System.out.printf( "[%llu] ", twonm1 / gcdResult );
	    if (outformat == 0) PrintBitString( n, m );
	    if (outformat == 1) PrintCoefString(n, m );
	    if (outformat == 2) PrintPoly( n, m );
	    printed++;
	}

public void PrintIt( long p ) {
  		long necklace;
  		long m, m_rev;
  		long gcdResult;
  		int i;
  		int count = 0;

if (p != n) return;

if ((maxNumber == 1) && (checked++ >= maxNumber)) {
    		System.out.println("Iteration limit exceeded !!");
    		doneFlag = true;
    		return;
  		}

necklace = toInt();
  		m = minpoly( n, necklace, prim_poly );

/* check if it's primitive */
  		gcdResult = gcd( necklace, twonm1 );
  		m_rev = computeReverse( n, m );
  		++ir_count;
  		if ( m != m_rev ) ++ir_count;

if ( gcdResult == 1 ) {
    		++pr_count;
    		OutputPolys( n, m, gcdResult );
    		if ( m != m_rev ) {
       			++pr_count;
       			OutputPolys( n, m_rev, gcdResult );
    		}
  		}
  		if ((maxNumber == 1) && (printed >= maxNumber)) {
    		System.out.println("Print limit exceeded !!");
    		doneFlag = true;
  		}
	}

public void gen( int t, int p, int c ) {
  		if (doneFlag) return;
  		if (t > n) PrintIt( p );
  		else {
    		if (b[t-c] == 0) {
      			if (b[t-p] == 0) {
        			b[t] = 0;
        			gen( t+1, p, t );
      			}
      			b[t] = 1;
      			if (b[t-p] == 1)
      				gen( t+1, p, c );
      			else
      				gen( t+1, t, c );
    		} else {
     			 b[t] = 0;
     			 gen( t+1, p, c );
    		}
  		}
	}

public static void main(String... args) {
		Poly p = new Poly();
		Scanner c = new Scanner(System.in);
		System.out.println("Enter n(degree) : ");
		p.n = Integer.parseInt(c.next());
		System.out.println("Enter format(0:String 1:Coeffs 2:Polys) : ");
		p.outformat = Integer.parseInt(c.next());
		p.display();
		p.prim_poly = p.poly_table[p.n];
		System.out.println(p.prim_poly);
		p.twonm1 = (int)(Math.pow(2,p.n)-1);
		b[0] = b[1] = 0;
		p.gen( 2, 1, 1 );
		System.out.println("No of primitive polynomials : "+p.pr_count);
	}
	
}

Please provide more details. What is the algorithm you are using? What sort of errors are you suffering?