Psudo-number Generator Using Mersenne Twister Algorithm Implemented in C/C++

leothenerd 2:58 pm on December 6, 2009 | Answers: 1    
Tags: algorithm (6), generator (5), mersenne, twister

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• leothenerd 2:58 pm on December 6, 2009
  

  #define N 624
  #define M 397
  #define MATRIX_A 0x9908b0dfUL  
  #define UPPER_MASK 0x80000000UL
  #define LOWER_MASK 0x7fffffffUL
  
  static unsigned long mt[N];  
  static int mti=N+1;          
  static unsigned long mag01[2] = {0x0UL, MATRIX_A};
  
  void MersenneTwister::init_genrand(unsigned long seed) {
    mt[0]= seed & 0xffffffffUL;
    for (mti = 1; mti = N) 
         { 
  
      if (mti == (N + 1))
        init_genrand(4537);
      int kk;
      for (kk = 0; kk > 1) ^ mag01[y & 0x1UL];
      }
      
      for (; kk> 1) ^ mag01[y & 0x1UL];
      }
      y = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
      mt[N-1] = mt[M-1] ^ (int)(y >> 1) ^ mag01[y & 0x1UL];
      mti = 0;
    }
  
    y = mt[mti++];
  
    y ^= (y >> 11);
    y ^= (y << 7) & 0x9d2c5680UL;
    y ^= (y <> 18);
  
    if (max == 0)
      return 0;
    else
      return (int)(y / 32) % max;
  }
  
  int main() {
         // Usage sample
    MersenneTwister *mt = new MersenneTwister(3);
    printf("%lu ", mt->genrandUInt32(125463));
    
    return 0;
  }