int maxPoints(pt* points, int pointsS) {
ht = NULL;
if(pointsS <= 1 || !points) return pointsS;
/* first check any point is duplicated, and for how many times */
int dup[pointsS];
memset(dup, 0, sizeof(int)*pointsS);
for(int i = 0; i <pointsS-1; i++)
for(int j = i+1; j< pointsS && dup[i]!= -1; j++)
if(isSame(points+i, points+j))
{
dup[i]++;
dup[j] = -1;
}
/* the algorithm is looping through each point,
check the line it's forming with each point after it,
and update a counter for each line in the hast table
then finally find the line with the largest count
*/
ln l;
map* s;
for(int i = 0; i<pointsS-1; i++)
{
for(int j = i+1; j<pointsS && dup[i] !=-1; j++)
{
getLine(points+i, points + j, &l);
s = htFind(l);
if(s)
{
/* an existing line, check if created by this point only */
if(i == s->idxCrt)
(s->numPt)++;
}
else
{
/* insert the new line */
if(isSame(points+i, points+j))
htAdd(l, 2, i); /* special case: same point */
else
htAdd(l, 2+dup[i], i); /* 2+dup points on a line */
}
}
}
/* htPrint(); */
/* find the largest count in the hasttable */
int ret = INT_MIN;
for(s=ht; s; s=(map*)(s->hh.next))
ret = (ret>s->numPt)? ret: s->numPt;
htCleanup();
return ret;
}
GdbStatus
gdbAddDataEntry(GDatabase *db, GdbHashTable *table, unsigned short key,
const void *data, long size)
{
if (db == NULL || db->fp == NULL || key == 0 || table == NULL ||
data == NULL || size == 0)
{
return GDB_ERROR;
}
htAdd(table, key, data, size, GDB_HT_RAW);
return GDB_SUCCESS;
}
int
main(int argc,char **argv)
{
HASHTABLE ht;
char * s;
int i;
ht = htMake(-1);
for (i = 0; i < argc; i++)
htAdd(ht,argv[i],(void*)argv[i]);
printf("\nContents of hash table: %d items, %d slots\n",
htItems( ht ), htSize( ht ) );
htWalk(ht,1,pfunc);
printf("\n===============\n");
while (1)
{
printf("Conflicts in table: %d\n",htConflicts(ht));
htWalk(ht,0,pfunc);
printf("\n");
printf("Enter key to remove: (\"quit\" to stop): ");
s = get_string();
if (!strcmp(s,"quit"))
break;
printf("Removing element with key \"%s\"... = %s\n",s,
nullstr((char*)htRemove(ht,s)));
}
printf("Closing hash table\n" );
htCloseWithFunction( ht, close_func );
return 0;
}
