void graph<vertex_type>::DijkstraPath( const vertex_type & start_vertex )
{
BinomialQueue< vertex<vertex_type> > q;
for(auto pair: graph_)
{
pair.second->clearDijkstra();
}
vertex<vertex_type>* s = (graph_[start_vertex]);
s->dist = 0;
q.insert(*s);
while( !q.isEmpty() )
{
vertex<vertex_type> v;
q.deleteMin(v);
graph_[v.name]->known = true;
//cout << "\n@@@@@@@@@@@DEQUEUED: graph_[v.name]: " << graph_[v.name]->name << " @@@@@@@@@@@" << endl;
for(auto w : v.adj) //adj is: list< pair <vertex<vertex_type>*, double> > adj
if( !(w.first)->known )
{
//cout << "\ngraph_[w.first->name] " << graph_[w.first->name]->name << endl;
DistType cost_v_to_w = w.second;
if( v.dist + cost_v_to_w < (w.first)->dist )
{
//cout << " w: " << (w.first->name) << endl;
q.decreaseKey( *(w.first), (v.dist + cost_v_to_w) );
w.first->dist = (v.dist + cost_v_to_w);
w.first->path = graph_[v.name];
if(!q.contains( *(w.first) ) )
q.insert( *(w.first) );
}
}
//cout << "q.isEmpty() : " << q.isEmpty() << endl;
}
}
void testBQ( const string & fileName )
{
cout << "\n********** Priority queues **********\n\n";
ifstream f1;
f1.open( fileName.c_str() );
if( f1.fail( ) ){
cout << "Error opening " << fileName;
exit( 1 );
}
int numItems = 10000;
cout << "Part 1. Inserting words in Binomial Queue\n";
BinomialQueue BQ;
HashTable HT ( BUCKET_SIZE );
string wordToSearch, line;
int numberOfLines = 1;
BQ.setNumberOfComparisonsAndAssignments( 0, 0 );
while( f1 ){ // read the document file
getline( f1, line );
string::iterator it;
for( it = line.begin( ); it < line.end( ); it++ ){
if( isspace( *it ) || ( ispunct( *it ) && *it != 39) ){
// || *it == 34){
if( wordToSearch != "" && !HT.contains( wordToSearch ) ){
BinomialNode *bn = BQ.insert( wordToSearch, numberOfLines );
// BinomialNode *bn = BQ.insertFast( wordToSearch, numberOfLines );
HT.insert( wordToSearch , bn );
}
else if( HT.contains( wordToSearch ) ){
HT.updateLineNumberForWord( wordToSearch, numberOfLines );
}
wordToSearch.clear();
continue;
}
else{
wordToSearch += *it; // build up the word
}
}
numberOfLines++;
line.clear(); // prepare to read a new line
}
cout << BQ.getCurrentSize( ) << " items inserted in Binomial Queue\n\n";
// BQ.printRoots( ); // debugging
/************************************************************
* (2) Count and print out the total number of comparisons
* and assignments executed for the insertions of all the
* N elements into the binomial queue.
***********************************************************/
cout << "Part 2. Print out number of operations\n";
cout << "Number of comparisons : " << BQ.getCmps( ) << endl;
cout << "Number of assignments : " << BQ.getAsmts( ) << endl;
/************************************************************
* (3) Test the deleteMin() operation by applying a sequence
* of 10 deleteMin() and by printing out the result (i.e. key
* deleted along with associated line numbers).
***********************************************************/
cout << "\nPart 3. ";
cout << "Executing 10 deleteMin() operations:\n";
for( int i = 0; i < 10; ++i ){
string minValue = BQ.findMin( ); // save element for printing line numbers
cout << "Min. val.: " << setw( 10 ) << left << minValue << " "; // print element
HT.printLineNumbersForWord( minValue );
BQ.deleteMin( ); // delete here.
HT.remove( minValue );
}
cout << endl;
/************************************************************
* (4) Test the function find() as follows: Prompt the user
* to input a string key. Execute the private function
* find(key). If find returns a pointer to a node that indeed
* holds key printout that find() was successful; printout
* the set of line numbers as well. Otherwise, printout that
* find() did not find the key.
***********************************************************/
cout << "Part 4. Testing find() function [once]:\n";
cout << "Enter a string key: ";
string key;
cin >> key;
BinomialNode *keyNode1 = HT.find( key );
if( keyNode1 ){
cout << "find() function found the key \"" << key << "\"";
cout << " in lines: ";
HT.printLineNumbersForWord( key );
cout << endl;
}
else{
cout << "find() function did not find the key \"" << key << "\"" << endl;
}
// delete keyNode1;
/******************************************************************
* (5) You are ready to implement now the remove(key) operation.
* For a given key, find its position p (p is a pointer) in the
* priority queue using the hash table. If the key is found delete
* it from the bq (Hint: your code should percolate the key up all
* the way to the root and then delete the root). Test your
* implementation by applying a sequence of remove(key) operations,
* and verify their correctness. For instance after remove(key),
* find(key) should return “not found”. Prompt the user 5 times
* to input a key. Execute then the remove(key) operation and
* verify (by printing whether the removal was successful or not).
*****************************************************************/
cout << "Part 5. Removing 5 keys and verifying the result" << endl;
key = "";
// BinomialNode *keyNode2;
for( int i = 0; i < 5; ++i ){
cout << "Enter a key to remove: ";
cin >> key;
BinomialNode *keyNode2 = HT.find( key );
if( keyNode2 ){
cout << "The key: \"" << key << "\" is removed " << endl;
BQ.remove( keyNode2 ); // remove from Binomial Queue
HT.remove( key ); // update Hash Table as well
cout << "Trying to find it..." << endl;
BinomialNode *temp = HT.find( key );
if( temp ) // this should not happen
cout << "Hmm.. \"" << temp->element << "\" found!" << endl;
else // good!
cout << "Good! Deletion is successful" << endl;
// cout << BQ.getCurrentSize( ); // debugging
// BQ.printRoots( );
}
else{
cout << "Cannot remove because the key \"" << key << "\" was not found" << endl;
}
}
/******************************************************************
* (6) Write a faster insert(key) function for the binomial queue.
* In order to achieve that you have to modify the merge() function
* and make it specific to the merging of one element only.
*****************************************************************/
cout << "\nPart 6. Testing fast insert(key) function [5 times]\n";
cout << "Keys will be inserted in line 0\n";
for( int i = 0; i < 5; ++i ){
key = "";
cout << "Enter a key to insert: ";
cin >> key;
BinomialNode *bn = BQ.insertFast( key, 0 );
HT.insert( key , bn );
cout << "\"" << key << "\" inserted in Binomial Queue at address: " << bn << endl;
cout << "\"" << key << "\" found in Hash Table and has pointer: " << HT.find( key ) << endl;
// cout << BQ.getCurrentSize( ); // debugging
// BQ.printRoots( );
}
cout << "\nPart 6a. Checking the improvement of insertFast() function over the original insert() function [3 times]: \n";
for( int i = 0; i < 3; ++i ){
string w3 = "";
cout << "\nEnter the key to check: ";
cin >> w3;
BQ.setNumberOfComparisonsAndAssignments( 0, 0 );
cout << "insert(\"" << w3 << "\", 10 )\n";
BinomialNode *bn = BQ.insert( w3, 10 );
HT.insert( "w3", bn );
cout << "\t\tNumber of comparisons = " << BQ.getCmps( ) << endl;
cout << "\t\tNumber of assignments = " << BQ.getAsmts( );
// BQ.printRoots( );
cout << "\nNow remove it, reset the counters and test in again:\n\n";
BQ.remove( bn );
HT.remove( "w3");
BQ.setNumberOfComparisonsAndAssignments( 0, 0 );
cout << "insertFast(\"" << w3 << "\", 10 )\n";
BinomialNode *bn2 = BQ.insertFast( w3, 10 );
HT.insert( "w3", bn2 );
cout << "\t\tNumber of comparisons = " << BQ.getCmps( ) << endl;
cout << "\t\tNumber of assignments = " << BQ.getAsmts( );
// BQ.printRoots( );
}
////////////////////////////////////////////////////////////////////////////////
f1.close();
cout << endl << "End of program. Thanks" << endl;
}