text: #include "sample.h"
  
  static uint16_t mod3(uint16_t a) {
      uint16_t r;
      int16_t t, c;
  
      r = (a >> 8) + (a & 0xff); // r mod 255 == a mod 255
      r = (r >> 4) + (r & 0xf); // r' mod 15 == r mod 15
      r = (r >> 2) + (r & 0x3); // r' mod 3 == r mod 3
      r = (r >> 2) + (r & 0x3); // r' mod 3 == r mod 3
  
      t = r - 3;
      c = t >> 15;
  
      return (c & r) ^ (~c & t);
  }
  
  void PQCLEAN_NTRUHRSS1373_CLEAN_sample_iid(poly *r, const unsigned char uniformbytes[NTRU_SAMPLE_IID_BYTES]) {
      int i;
      /* {0,1,...,255} -> {0,1,2}; Pr[0] = 86/256, Pr[1] = Pr[-1] = 85/256 */
      for (i = 0; i < NTRU_N - 1; i++) {
          r->coeffs[i] = mod3(uniformbytes[i]);
      }
  
      r->coeffs[NTRU_N - 1] = 0;
  }
  