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digitalmars.D.learn - BinaryHeap

reply "Agustin" <agustin.l.alvarez hotmail.com> writes:
I'm trying to use BinaryHeap and i found out that i cannot use 
foreach(). My question is, there is any other way to do it?, can 
i iterate a BinaryHeap?
Nov 06 2013
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
Agustin:


 I'm trying to use BinaryHeap and i found out that i cannot use 
 foreach(). My question is, there is any other way to do it?, 
 can i iterate a BinaryHeap?


Please show the code :-)

Perhaps you need to look at the head, pop the head item, look at 
the head, etc.

Bye,
bearophile
Nov 07 2013
parent reply "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 09:00:11 UTC, bearophile wrote:

 Agustin:


 I'm trying to use BinaryHeap and i found out that i cannot use 
 foreach(). My question is, there is any other way to do it?, 
 can i iterate a BinaryHeap?


 Please show the code :-)

 Perhaps you need to look at the head, pop the head item, look 
 at the head, etc.

 Bye,
 bearophile


     BinaryHeap!(uint[]) heap;
     foreach(type; heap)
     {
      ....
     }

no property 'popFront' for type 'BinaryHeap!(uint[])'
Nov 07 2013
next sibling parent "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 12:14:22 UTC, Agustin wrote:

 On Thursday, 7 November 2013 at 09:00:11 UTC, bearophile wrote:

 Agustin:


 I'm trying to use BinaryHeap and i found out that i cannot 
 use foreach(). My question is, there is any other way to do 
 it?, can i iterate a BinaryHeap?


 Please show the code :-)

 Perhaps you need to look at the head, pop the head item, look 
 at the head, etc.

 Bye,
 bearophile


     BinaryHeap!(uint[]) heap;
     foreach(type; heap)
     {
      ....
     }

 no property 'popFront' for type 'BinaryHeap!(uint[])'


It seems that i need to have a pointer to the underlying array.

     uint[] intArray;
     BinaryHeap!(uint[]) heap;
     heap.acquire(intArray);
     foreach(int; intArray)
     {
      ....
     }
Nov 07 2013
prev sibling parent reply "bearophile" <bearophileHUGS lycos.com> writes:
Agustin:


 no property 'popFront' for type 'BinaryHeap!(uint[])'


Try to use front and removeFront (I don't know why there is 
removeFront instead of popFront).

Bye,
bearophile
Nov 07 2013
next sibling parent reply "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 12:29:44 UTC, bearophile wrote:

 Agustin:


 no property 'popFront' for type 'BinaryHeap!(uint[])'


 Try to use front and removeFront (I don't know why there is 
 removeFront instead of popFront).

 Bye,
 bearophile


Saddly i had to do this

     auto clone = _heap.dup;

     while (!clone.empty())
     {
         auto item = clone.front();
         // ... Do something with item
         clone.removeFront();
     }

Iterate directly over a binary heap will be better perfomance 
wise than doing that because i had to clone the heap to be able 
to iterate over without removing items from the original heap.
Nov 07 2013
parent "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 12:45:11 UTC, Agustin wrote:

 On Thursday, 7 November 2013 at 12:29:44 UTC, bearophile wrote:

 Agustin:


 no property 'popFront' for type 'BinaryHeap!(uint[])'


 Try to use front and removeFront (I don't know why there is 
 removeFront instead of popFront).

 Bye,
 bearophile


 Saddly i had to do this

     auto clone = _heap.dup;

     while (!clone.empty())
     {
         auto item = clone.front();
         // ... Do something with item
         clone.removeFront();
     }

 Iterate directly over a binary heap will be better perfomance 
 wise than doing that because i had to clone the heap to be able 
 to iterate over without removing items from the original heap.


By looking at the source, having "private  property ref Store 
_store()" public will help a lot.
Nov 07 2013
prev sibling parent reply "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 12:29:44 UTC, bearophile wrote:

 Agustin:


 no property 'popFront' for type 'BinaryHeap!(uint[])'


 Try to use front and removeFront (I don't know why there is 
 removeFront instead of popFront).

 Bye,
 bearophile


I had to implement a custom IterableBinaryHeap implementation.

http://pastebin.com/GeVAeCch

     IterableBinaryHeap!(Array!uint, "a < b") heap;
     heap.insert(0);
     heap.insert(3);
     heap.insert(2);
     heap.insert(1);
     foreach(item; heap)
         writeln(item);
Nov 07 2013
parent "Agustin" <agustin.l.alvarez hotmail.com> writes:
On Thursday, 7 November 2013 at 14:31:27 UTC, Agustin wrote:

 On Thursday, 7 November 2013 at 12:29:44 UTC, bearophile wrote:

 Agustin:


 no property 'popFront' for type 'BinaryHeap!(uint[])'


 Try to use front and removeFront (I don't know why there is 
 removeFront instead of popFront).

 Bye,
 bearophile


 I had to implement a custom IterableBinaryHeap implementation.

 http://pastebin.com/GeVAeCch

     IterableBinaryHeap!(Array!uint, "a < b") heap;
     heap.insert(0);
     heap.insert(3);
     heap.insert(2);
     heap.insert(1);
     foreach(item; heap)
         writeln(item);


The above code was working until i upgrade to DMD32 D Compiler 
v2.064.

Now i got:
   "Error: cannot uniquely infer foreach argument types"

Help!
Nov 27 2013