-// A fast 32-bit linear congruential random number generator
-class quick_rng
-{
- unsigned long next;
-public:
- quick_rng(unsigned long seed=0):next(seed) { }
-
- void set_seed(unsigned long x)
- {
- next=x;
- }
-
- unsigned long i32()
- {
- static const unsigned long a(1664525);
- static const unsigned long c(1013904223);
-
- return next=next*a+c;
- }
-
- unsigned long i16()
- {
- return i32()>>16;
- }
-
- float f()
- {
- static const float m(int(65535));
-
- return float(i16())/m;
- }
-
- unsigned long operator()(const unsigned long& m)
- {
- if(m==65536)
- return i16();
- else
- if(m<=65536)
- return i16()%m;
- else
- return i32()%m;
- }
-};
-