int main()
{
/*Will hold the position of the substring if exists in the tree.*/
DBL_WORD position;
/*Create the suffix tree*/
SUFFIX_TREE* tree = ST_CreateTree("mississippi", 11);
/*Print the suffix tree.*/
ST_PrintTree(tree);
/*Search for a substring in the tree and return its position if exists.*/
position = ST_FindSubstring(tree, "ssis", 4);
/*Print the position of the substring*/
printf("\nPosition of ssis in mississippi is %ld.\n\n", position);
/*Delete the tree and all its nodes.*/
ST_DeleteTree(tree);
}
void SEA(
SUFFIX_TREE* tree,
POS* pos,
PATH str,
DBL_WORD* rule_applied,
char after_rule_3)
{
DBL_WORD chars_found = 0 , path_pos = str.begin;
NODE* tmp;
#ifdef DEBUG
ST_PrintTree(tree);
printf("extension: %lu phase+1: %lu",str.begin, str.end);
if(after_rule_3 == 0)
printf(" followed from (%lu,%lu | %lu) ", pos->node->edge_label_start, get_node_label_end(tree,pos->node), pos->edge_pos);
else
printf(" starting at (%lu,%lu | %lu) ", pos->node->edge_label_start, get_node_label_end(tree,pos->node), pos->edge_pos);
#endif
#ifdef STATISTICS
counter++;
#endif
/* Follow suffix link only if it's not the first extension after rule 3 was applied */
if(after_rule_3 == 0)
follow_suffix_link(tree, pos);
#ifdef DEBUG
#ifdef STATISTICS
if(after_rule_3 == 0)
printf("to (%lu,%lu | %lu). counter: %lu\n", pos->node->edge_label_start, get_node_label_end(tree,pos->node),pos->edge_pos,counter);
else
printf(". counter: %lu\n", counter);
#endif
#endif
/* If node is root - trace whole string starting from the root, else - trace last character only */
if(pos->node == tree->root)
{
pos->node = trace_string(tree, tree->root, str, &(pos->edge_pos), &chars_found, no_skip);
}
else
{
str.begin = str.end;
chars_found = 0;
/* Consider 2 cases:
1. last character matched is the last of its edge */
if(is_last_char_in_edge(tree,pos->node,pos->edge_pos))
{
/* Trace only last symbol of str, search in the NEXT edge (node) */
tmp = find_son(tree, pos->node, tree->tree_string[str.end]);
if(tmp != 0)
{
pos->node = tmp;
pos->edge_pos = 0;
chars_found = 1;
}
}
/* 2. last character matched is NOT the last of its edge */
else
{
/* Trace only last symbol of str, search in the CURRENT edge (node) */
if(tree->tree_string[pos->node->edge_label_start+pos->edge_pos+1] == tree->tree_string[str.end])
{
pos->edge_pos++;
chars_found = 1;
}
}
}
/* If whole string was found - rule 3 applies */
if(chars_found == str.end - str.begin + 1)
{
*rule_applied = 3;
/* If there is an internal node that has no suffix link yet (only one may
exist) - create a suffix link from it to the father-node of the
current position in the tree (pos) */
if(suffixless != 0)
{
create_suffix_link(suffixless, pos->node->father);
/* Marks that no internal node with no suffix link exists */
suffixless = 0;
}
#ifdef DEBUG
printf("rule 3 (%lu,%lu)\n",str.begin,str.end);
#endif
return;
}
/* If last char found is the last char of an edge - add a character at the
next edge */
if(is_last_char_in_edge(tree,pos->node,pos->edge_pos) || pos->node == tree->root)
{
/* Decide whether to apply rule 2 (new_son) or rule 1 */
if(pos->node->sons != 0)
{
/* Apply extension rule 2 new son - a new leaf is created and returned
by apply_extension_rule_2 */
apply_extension_rule_2(pos->node, str.begin+chars_found, str.end, path_pos, 0, new_son);
*rule_applied = 2;
/* If there is an internal node that has no suffix link yet (only one
may exist) - create a suffix link from it to the father-node of the
current position in the tree (pos) */
if(suffixless != 0)
{
create_suffix_link(suffixless, pos->node);
/* Marks that no internal node with no suffix link exists */
suffixless = 0;
}
}
}
else
{
/* Apply extension rule 2 split - a new node is created and returned by
apply_extension_rule_2 */
tmp = apply_extension_rule_2(pos->node, str.begin+chars_found, str.end, path_pos, pos->edge_pos, split);
if(suffixless != 0)
create_suffix_link(suffixless, tmp);
/* Link root's sons with a single character to the root */
if(get_node_label_length(tree,tmp) == 1 && tmp->father == tree->root)
{
tmp->suffix_link = tree->root;
/* Marks that no internal node with no suffix link exists */
suffixless = 0;
}
else
/* Mark tmp as waiting for a link */
suffixless = tmp;
/* Prepare pos for the next extension */
pos->node = tmp;
*rule_applied = 2;
}
}