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geqo_recombination.c File Reference
Include dependency graph for geqo_recombination.c:

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Functions

void init_tour (PlannerInfo *root, Gene *tour, int num_gene)
 

Function Documentation

◆ init_tour()

void init_tour ( PlannerInfo root,
Gene tour,
int  num_gene 
)

Definition at line 34 of file geqo_recombination.c.

35{
36 int i,
37 j;
38
39 /*
40 * We must fill the tour[] array with a random permutation of the numbers
41 * 1 .. num_gene. We can do that in one pass using the "inside-out"
42 * variant of the Fisher-Yates shuffle algorithm. Notionally, we append
43 * each new value to the array and then swap it with a randomly-chosen
44 * array element (possibly including itself, else we fail to generate
45 * permutations with the last city last). The swap step can be optimized
46 * by combining it with the insertion.
47 */
48 if (num_gene > 0)
49 tour[0] = (Gene) 1;
50
51 for (i = 1; i < num_gene; i++)
52 {
53 j = geqo_randint(root, i, 0);
54 /* i != j check avoids fetching uninitialized array element */
55 if (i != j)
56 tour[i] = tour[j];
57 tour[j] = (Gene) (i + 1);
58 }
59}
int Gene
Definition: geqo_gene.h:30
int geqo_randint(PlannerInfo *root, int upper, int lower)
Definition: geqo_random.c:36
int j
Definition: isn.c:73
int i
Definition: isn.c:72
tree ctl root
Definition: radixtree.h:1857

References geqo_randint(), i, j, and root.

Referenced by random_init_pool().