#ifndef J_RANDOM_H
#define J_RANDOM_H

struct Random
{
	unsigned long long seed;

	Random() : seed(0x0000A6B5C4D3E2F1LL) {}

	Random(long long seed)
	{
		setSeed(seed);
	}

	void setSeed(long long newSeed)
	{
		seed = newSeed ^ 0x00000005DEECE66DLL;
	}

	int next(int bits)
	{
		seed *= 0x00000005DEECE66DLL;
		seed += 0x000000000000000BLL;
		seed &= 0x0000FFFFFFFFFFFFLL;
		return (int) (seed >> (48 - bits));
	}

	int nextInt()
	{
		return next(32);
	}

	int nextInt(int n)
	{
		if ((n & -n) == n) // if n only has 1 bit set (n is a power of 2)
		{
			long long x = next(31);
			x *= n;
			return (int)(x >> 31);
		}

		int bits, val;

		do
		{
			bits = next(31);
			val = bits % n;
		} while (bits - val + (n-1) < 0);

		return val;
	}

	long long nextLong()
	{
		long long x = next(32);
		x <<= 32;
		return x + next(32);
	}

	double nextDouble() 
	{
		long long x = next(26);
		x <<= 27;
		x += next(27);
		return x / 9007199254740992.0;
	}

	bool nextBoolean()
	{
		return next(1) != 0;
	}
};

#endif