sample.h

eC++编译器源码

#pragma Sample


  /* Floyd's Algorithm CACM 9(Sept. 1987) 754-757. */


  /* A random sample of size M out of 1..N i.e. M distinct
     random numbers, which lie in the range 1..N  */

     
  /* Comments only by Rohit Wad rvw2k */

  typedef void *Stream;

  void Samples(unsigned int M, unsigned int N, unsigned int &result[]);
  /* This procedure produces one random Sample and stores it in the 
     array result. */


  void Open(Stream &s, unsigned int M, unsigned int N, unsigned int &result[]);
    /* result holds the first permutation */
    /* but, a fixed one. This permutation is simply a descending
       series that generates all permutations. */


  boolean Next(Stream &s); /* returns remaining permutations of M/N*/
    /* The remaining permutations are to be stored in the array
       'result' from Open. */


  void Close(Stream &s);
    /* To deallocate space */