scout.c

   1 #include <stdlib.h>
   2 #include "scout.h"
   3
   4 typedef struct scnode scnode;
   5 typedef struct scway scway;
   6 typedef struct scwaypoint scwaypoint;
   7
   8 scway *scaddway(scnode *from, const scnode *to, int len)
   9 {
  10         scway *way = malloc(sizeof(scway));
  11         way->lto = to;
  12         way->alt = NULL;
  13         way->len = len;
  14         scway *apar, *par = NULL;
  15         for (apar = from->way; apar != NULL; par = apar, apar = apar->alt);
  16         if (par)
  17                 par->alt = way;
  18         else
  19                 from->way = way;
  20         return way;
  21 }
  22
  23 scwaypoint *__scallocwayp(const scnode *node, scway *way)
  24 {
  25         scwaypoint *wayp = malloc(sizeof(scwaypoint));
  26         wayp->nod = node;
  27         wayp->way = way;
  28         wayp->nxt = NULL;
  29         wayp->len = 0;
  30 }
  31
  32 scwaypoint *__scstackfindgetend(scwaypoint *stack, scway *way)
  33 {
  34         scwaypoint *asptr, *sptr;
  35         for (asptr = stack; asptr != NULL; sptr = asptr, asptr = asptr->nxt)
  36                 if (asptr->nod == way->lto)
  37                         return NULL;
  38         return sptr;
  39 }
  40
  41 void __scstackfree(scwaypoint *stack)
  42 {
  43         for (scwaypoint *sptr = stack; sptr != NULL; sptr = sptr->nxt)
  44                 free(sptr);
  45 }
  46
  47 int __scstackgetlen(scwaypoint *stack)
  48 {
  49         for (scwaypoitn)
  50 }
  51
  52 scwaypoint *scout(const scnode *from, const scnode *to, scwaypoint *stack)
  53 {
  54         scwaypoint *wayp = NULL;
  55         if (from == to)
  56                 return __scallocwayp(from, NULL);
  57         for (scway *way = from->way; way != NULL; way = way->alt) {
  58                 scwaypoint *stackend;
  59                 if ((stackend = __scstackfindgetend(stack, way)) == NULL)
  60                         continue;
  61
  62                 if (wayp && wayp->len <= (tway->len = __scstackgetlen(tway)))
  63                         __scstackfree(wayp);
  64                 wayp = twayp;
  65         }
  66         return wayp;
  67 }