#ifndef louvain_random
#define louvain_random

#include <cstdlib>
#include <chrono>

using namespace std::chrono;

class Random {
  long seed;
public:
  Random(long _seed):seed(_seed) {
  }

  Random() {
    seed = duration_cast< milliseconds >(system_clock::now().time_since_epoch()).count();
  }

  double nextDouble() {
    // Robert Jenkins' 32 bit integer hash function.
    seed = ((seed + 0x7ed55d16) + (seed << 12)) & 0xffffffff;
    seed = ((seed ^ 0xc761c23c) ^ (seed >> 19)) & 0xffffffff;
    seed = ((seed + 0x165667b1) + (seed << 5)) & 0xffffffff;
    seed = ((seed + 0xd3a2646c) ^ (seed << 9)) & 0xffffffff;
    seed = ((seed + 0xfd7046c5) + (seed << 3)) & 0xffffffff;
    seed = ((seed ^ 0xb55a4f09) ^ (seed >> 16)) & 0xffffffff;
    return static_cast <double> (seed & 0xfffffff) / static_cast <double> (0x10000000);
  }

  double next(double max) {
    return nextDouble() * max;
  }
};

#endif