// return all p3 in p3_set with (*,*,v)
set<t_3path> t_dir_graph::get_p3_by_third(const t_vertex& v) const{
set<t_vertex> pred, predpred;
set<t_3path> result;
pred = get_predecessors(v);
for(set<t_vertex>::const_iterator u = pred.begin(); u!= pred.end(); u++){
predpred = get_predecessors(*u);
for(set<t_vertex>::const_iterator w = predpred.begin(); w!= predpred.end(); w++)
if(p3_set.find(t_3path(t_arc(*w,*u),t_arc(*u,v))) != p3_set.end())
result.insert(t_3path(t_arc(*w,*u),t_arc(*u,v)));
}
return result;
}
// mark an arc forbidden/permanent,
// note that, if adjacent arcs are also forbidden/permanent, this mark may cascade
bool t_dir_graph::mark_arc(const t_arc& a, const uint mark){
if(successors.find(a.first) == successors.end()) return false; // dont mark edges that are not in VxV
if(successors.find(a.second) == successors.end()) return false; // dont mark edges that are not in VxV
dbgcout << "marking " << a << (mark==MRK_NONE?"none":(mark==MRK_FORBIDDEN?"forbidden":"permanent")) << "\n";
bool result = true;
switch(mark){
case MRK_NONE:
return (forbidden_arcs.erase(a) || permanent_arcs.erase(a));
break;
case MRK_FORBIDDEN:
if((!contains_arc(a)) && (forbidden_arcs.find(a) == forbidden_arcs.end())
&& forbidden_arcs.insert(a).second) {
set<t_vertex> belt = set_intersect(get_successors(a.first), get_predecessors(a.second));
for(set<t_vertex>::iterator u = belt.begin(); u != belt.end(); u++){
if(permanent_arcs.find(t_arc(a.first, *u)) != permanent_arcs.end())
result &= mark_arc(t_arc(*u, a.second), MRK_FORBIDDEN);
if(permanent_arcs.find(t_arc(*u, a.second)) != permanent_arcs.end())
result &= mark_arc(t_arc(a.first, *u), MRK_FORBIDDEN);
}
return result;
} else return false;
break;
case MRK_PERMANENT:
if(contains_arc(a) && (permanent_arcs.find(a) == permanent_arcs.end())
&& permanent_arcs.insert(a).second) {
set<t_vertex> pred = get_predecessors(a.first);
for(set<t_vertex>::iterator u = pred.begin(); u != pred.end(); u++){
if(permanent_arcs.find(t_arc(*u, a.first)) != permanent_arcs.end())
result &= mark_arc(t_arc(*u, a.second), MRK_PERMANENT);
}
pred = set_substract(get_vertices(), get_predecessors(a.second));
for(set<t_vertex>::iterator u = pred.begin(); u != pred.end(); u++){
if(forbidden_arcs.find(t_arc(*u, a.second)) != forbidden_arcs.end())
result &= mark_arc(t_arc(*u, a.second), MRK_FORBIDDEN);
}
set<t_vertex> succ = get_successors(a.second);
for(set<t_vertex>::iterator u = succ.begin(); u != succ.end(); u++){
if(permanent_arcs.find(t_arc(a.second, *u)) != permanent_arcs.end())
result &= mark_arc(t_arc(a.first, *u), MRK_PERMANENT);
}
succ = set_substract(get_vertices(), get_successors(a.first));
for(set<t_vertex>::iterator u = succ.begin(); u != succ.end(); u++){
if(forbidden_arcs.find(t_arc(a.first, *u)) != forbidden_arcs.end())
result &= mark_arc(t_arc(a.second, *u), MRK_FORBIDDEN);
}
return result;
} else return false;
break;
default: return false;
}
}
// return all p3 in p3_set with (*,v,*)
set<t_3path> t_dir_graph::get_p3_by_middle(const t_vertex& v) const{
set<t_vertex> succ, pred;
set<t_3path> result;
succ = get_successors(v);
pred = get_predecessors(v);
for(set<t_vertex>::const_iterator u = pred.begin(); u!= pred.end(); u++)
for(set<t_vertex>::const_iterator w = succ.begin(); w!= succ.end(); w++)
if(p3_set.find(t_3path(t_arc(*u,v),t_arc(v,*w))) != p3_set.end())
result.insert(t_3path(t_arc(*u,v),t_arc(v,*w)));
return result;
}
// increase the belt size of the given diamond
// O(log n)
void t_dir_graph::increase_diamond(const t_diamond& diam){
map<t_diamond, uint>::iterator d_iter = diamond_set.find(diam);
// cout << "increasing diamond-belt of "<<diam<<"\n";
if(d_iter != diamond_set.end()){
d_iter->second++;
} else {// if its not there, maybe it should be inserted...
// this intersection can be calced in O(1), otherwise, diam would have been in diamond_set !
set<t_vertex> belt = set_intersect(get_successors(diam.first), get_predecessors(diam.second));
// cout << "oops, not yet there, "<<diam<<" is "<<(belt.size()>1?"":"not ")<<"inserted (size "<<belt.size()<<")\n";
if(belt.size() > 1)
diamond_set.insert(pair<t_diamond,uint>(diam, belt.size()));
}
}
// insert an arc
// O(n log n)
bool t_dir_graph::insert_arc(const t_arc& a, const bool permanent){
if(successors.find(a.second) == successors.end()) return false; // dont insert edges that are not in VxV
if(predecessors.find(a.first) == predecessors.end()) return false; // dont insert edges that are not in VxV
if(forbidden_arcs.find(a) != forbidden_arcs.end()) return false; // dont insert if the arc is forbidden
t_adjtable::iterator i = successors.find(a.first);
t_adjtable::iterator j = predecessors.find(a.second);
if((i != successors.end()) && (j != predecessors.end()))
if(i->second.insert(a.second).second)
if(j->second.insert(a.first).second){
if(permanent) mark_arc(a, MRK_PERMANENT);
// update p3_set and diamond_set
// first, remove all p3 destroyed by a
set<t_vertex> belt = set_intersect(i->second,j->second);
for(set<t_vertex>::const_iterator u = belt.begin(); u != belt.end(); u++)
p3_set.erase(t_3path(t_arc(a.first, *u),t_arc(*u, a.second)));
diamond_set.erase(t_diamond(a.first, a.second));
// second, add new P3 and diamonds
// u -> a.first -> a.second
set<t_vertex> pred = set_substract(get_predecessors(a.first), j->second);
pred.erase(a.second);
for(set<t_vertex>::const_iterator u = pred.begin(); u != pred.end(); u++){
increase_diamond(t_diamond(*u, a.second));
p3_set.insert(t_3path(t_arc(*u,a.first),a));
}
// a.first -> a.second -> u
set<t_vertex> succ = set_substract(get_successors(a.second), i->second);
succ.erase(a.first);
for(set<t_vertex>::const_iterator u = succ.begin(); u != succ.end(); u++){
increase_diamond(t_diamond(a.first, *u));
p3_set.insert(t_3path(a,t_arc(a.second, *u)));
}
return true;
} else {// avoid inconsistency
i->second.erase(a.second);
return false;
}
else return false;
else return false;
}
// calculate the reachability of v in D
// if undirected is true, all vertices can reach their predecessors
set<t_vertex> t_dir_graph::get_reachable(const t_vertex& v, bool undirected) const{
if(contains_vertex(v)){
set<t_vertex> to_check, checked, neighbors;
t_vertex u;
to_check.insert(v);
while(!to_check.empty()){
u = *(to_check.begin());
to_check.erase(to_check.begin());
neighbors = get_successors(u);
if(undirected) neighbors = set_unite(neighbors, get_predecessors(u));
neighbors = set_substract(neighbors, checked);
to_check = set_unite(to_check, neighbors);
checked.insert(u);
}
return checked;
} else return set<t_vertex>();
}
// delete an arc
// O(n log n)
bool t_dir_graph::delete_arc(const t_arc& a, const bool forbidden){
if(permanent_arcs.find(a) != permanent_arcs.end()) return false; // dont delete if the arc is permanent
t_adjtable::iterator i = successors.find(a.first);
t_adjtable::iterator j = predecessors.find(a.second);
if((i != successors.end()) && (j != predecessors.end()))
if(i->second.erase(a.second))
if(j->second.erase(a.first)){
if(forbidden) mark_arc(a, MRK_FORBIDDEN);
// update p3_set and diamond_set
// first, remove all p3 destroyed by a
// u -> a.first -> a.second
set<t_vertex> pred = set_substract(get_predecessors(a.first), j->second);
pred.erase(a.second);
for(set<t_vertex>::const_iterator u = pred.begin(); u != pred.end(); u++){
decrease_diamond(t_diamond(*u,a.second));
p3_set.erase(t_3path(t_arc(*u,a.first),t_arc(a.first, a.second)));
}
// a.first -> a.second -> u
set<t_vertex> succ = set_substract(get_successors(a.second), i->second);
succ.erase(a.first);
for(set<t_vertex>::const_iterator u = succ.begin(); u != succ.end(); u++){
decrease_diamond(t_diamond(a.first, *u));
p3_set.erase(t_3path(t_arc(a.first, a.second),t_arc(a.second, *u)));
}
// second, add new P3 and diamonds
set<t_vertex> belt = set_intersect(i->second,j->second);
for(set<t_vertex>::const_iterator u = belt.begin(); u != belt.end(); u++)
p3_set.insert(t_3path(t_arc(a.first, *u),t_arc(*u, a.second)));
if(belt.size()>1)
diamond_set.insert(
pair<t_diamond,uint>(t_diamond(a.first,a.second),belt.size())
);
return true;
} else return false;
else return false;
else return false;
}
// get all neighbors of v, that is successors and predecessors
set<t_vertex> t_dir_graph::get_neighbors(const t_vertex& v) const{
return set_unite(get_predecessors(v), get_successors(v));
}
int main(int argc, char **argv) {
char word[MAXWORDSIZE];
char cmd[MAXWORDSIZE]; /* string to hold a command */
char fname[MAXWORDSIZE]; /* name of input file */
PAGENO i;
int goOn;
int k;
setparms(); /* reads the pagesize and the number of ptrs/postigs_record */
dbopen(); /* opens or creates the three files (btree, postings, text) */
goOn = TRUE;
while (goOn) {
printf("\n\t*** These are your commands .........\n");
printf("\t\"C\" to scan the tree\n");
printf("\t\"i\" to insert\n");
printf("\t\"p\" to print a btree page\n");
printf("\t\"s\" to search, and print the key\n");
printf("\t\"S\" to search, and print the key, posting list pairs\n");
printf("\t\">\" to print k successors\n");
printf("\t\"<\" to print k predecessors\n");
printf("\t\"T\" to print the btree in inorder format\n");
printf("\t\"#\" to reset and print stats\n");
printf("\t\"x\" to exit\n");
/* printf("\"d\" to display statistics, \"c\" to clear them,\n"); */
scanf("%s", cmd);
assert(strlen(cmd) < MAXWORDSIZE);
switch (cmd[0]) {
case 'C':
printf("\n*** Scanning... \n");
scanTree(&printOcc);
break;
case 'i':
printf("\tgive input file name: ");
scanf("%s", fname);
assert(strlen(fname) < MAXWORDSIZE);
printf("\n*** Inserting %s\n", fname);
insert(fname);
break;
case 's':
printf("enter search-word: ");
scanf("%s", word);
assert(strlen(word) < MAXWORDSIZE);
printf("\n*** Searching for word %s \n", word);
search(word, FALSE);
break;
case 'S':
printf("enter search-word: ");
scanf("%s", word);
assert(strlen(word) < MAXWORDSIZE);
printf("\n*** Searching for word %s \n", word);
search(word, TRUE);
break;
case 'p':
printf("pagenumber=?\n");
scanf("%s", cmd);
assert(strlen(cmd) < MAXWORDSIZE);
i = (PAGENO) atoi(cmd);
printPage(i, fpbtree);
break;
case '>':
printf("word=?\n");
scanf("%s", word);
printf("k=?\n");
scanf("%d", &k);
get_successors(word, k, NULL);
break;
case '<':
printf("word=?\n");
scanf("%s", word);
printf("k=?\n");
scanf("%d", &k);
get_predecessors(word, k, NULL);
break;
case 'T':
printf("\n*** Printing tree in order .........\n");
PrintTreeInOrder(ROOT, 0);
break;
case '#':
printf("\n");
printFetchPageCnt();
printf("\n...reseted FetchPage counter\n");
break;
case 'x':
printf("\n*** Exiting .........\n");
goOn = FALSE;
break;
default:
printf("\n*** Illegal command \"%s\"\n", cmd);
break;
}
}
dbclose();
return (0);
}
