probdist.c

   1 #include <assert.h>
   2 #include <math.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5
   6 #include "move.h"
   7 #include "probdist.h"
   8 #include "random.h"
   9 #include "board.h"
  10
  11 int
  12 probdist_pick(struct probdist *pd)
  13 {
  14         float total = probdist_total(pd) - PROBDIST_EPSILON;
  15         assert(total >= 0);
  16         /* TODO: float random */
  17         double stab = fast_frandom() * total;
  18         //fprintf(stderr, "stab %f / %f\n", stab, total);
  19         for (int i = 0; i < pd->n; i++) {
  20                 //struct board b = { .size = 11 };
  21                 //fprintf(stderr, "[%s] %f (%f)\n", coord2sstr(i, &b), pd->items[i], stab);
  22                 if (stab <= pd->items[i])
  23                         return i;
  24                 stab -= pd->items[i];
  25         }
  26         fprintf(stderr, "overstab %f (total %f)\n", stab, total);
  27         assert(0);
  28         return -1;
  29 }