test_04.c

#include <stdint.h>
#include <stdio.h>
#include <string.h>

void
encode( uint32_t* a, uint32_t* b, int size )
{
  for (int i = 0; i < size; i++)
  {
    for (int j = 0; j < size; j++) 
    {
      b[(i + j) / 32] ^= ( (a[i / 32] >> (i % 32)) & (a[j / 32 + size / 32] >> (j % 32)) & 1 ) << ((i + j) % 32);   // Magic centaurian operation
    }
  }
}

void
print_32b( uint32_t a )
{
  for (int i=31;i>=0;i--)
  {
    printf("%c",a&(1<<i)?'1':'0');
  }
}

int
main( void )
{
  uint32_t a[ 2 ];
  uint32_t b[ 2 ];

  for (int i=0;i<32;i++)
  {
    a[0] = 0xffffffff;
    a[1] = 1<<i;
    b[0] = 0;
    b[1] = 0;

    encode( a,b,32 );

    printf("a ");
    print_32b(a[1]);
    printf(" ");
    print_32b(a[0]);
    printf("\n");

    printf("b ");
    print_32b(b[1]);
    printf(" ");
    print_32b(b[0]);
    printf("\n");

    printf("\n");
  }

  return 0;
}