10.1 The Combination struct

A combination is defined by a structure containing three components, the values of n and k, and a pointer to the combination array. The elements of the combination array are all of type size_t, and are stored in increasing order. The gsl_combination structure looks like this,

typedef struct
{
  size_t n;
  size_t k;
  size_t *data;
} gsl_combination;