Class: CompSci::CompleteTree

Inherits:
Object
  • Object
show all
Defined in:
lib/compsci/complete_tree.rb

Overview

A CompleteTree can very efficiently use an array for storage using simple arithmetic to determine parent child relationships.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(array: [], child_slots: 2) ⇒ CompleteTree

Returns a new instance of CompleteTree.


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# File 'lib/compsci/complete_tree.rb', line 28

def initialize(array: [], child_slots: 2)
  @array = array
  @child_slots = child_slots
end

Instance Attribute Details

#arrayObject (readonly)

Returns the value of attribute array.


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# File 'lib/compsci/complete_tree.rb', line 26

def array
  @array
end

Class Method Details

.children_idx(idx, n) ⇒ Object


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# File 'lib/compsci/complete_tree.rb', line 11

def self.children_idx(idx, n)
  Array.new(n) { |i| n*idx + i + 1 }
end

.gen(idx, n) ⇒ Object


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# File 'lib/compsci/complete_tree.rb', line 15

def self.gen(idx, n)
  count = 0
  loop {
    pidx = self.parent_idx(idx, n)
    break if pidx < 0
    count += 1
    idx = pidx
  }
  count
end

.parent_idx(idx, n) ⇒ Object

integer math maps several children to one parent


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# File 'lib/compsci/complete_tree.rb', line 7

def self.parent_idx(idx, n)
  (idx-1) / n
end

Instance Method Details

#bf_search(&blk) ⇒ Object

or, ya know, just iterate @array


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# File 'lib/compsci/complete_tree.rb', line 50

def bf_search(&blk)
  destinations = [0]
  while !destinations.empty?
    idx = destinations.shift
    return idx if yield @array[idx]

    # idx has a val and the block is false
    # add existent children to destinations
    self.class.children_idx(idx, @child_slots).each { |cidx|
      destinations.push(cidx) if cidx < @array.size
    }
  end
end

#df_search(&blk) ⇒ Object


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# File 'lib/compsci/complete_tree.rb', line 64

def df_search(&blk)
  puts "not yet"
end

#display(width: 80) ⇒ Object Also known as: to_s

TODO: fixme


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# File 'lib/compsci/complete_tree.rb', line 69

def display(width: 80)
  str = ''
  old_level = 0
  @array.each_with_index { |val, i|
    val = val.to_s
    level = self.class.gen(i, @child_slots)
    if old_level != level
      str += "\n"
      old_level = level
    end

    # center in block_width
    slots = @child_slots**level
    block_width = width / slots
    space = [(block_width + val.size) / 2, val.size + 1].max
    str += val.ljust(space, ' ').rjust(block_width, ' ')
  }
  str
end

#last_idxObject


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# File 'lib/compsci/complete_tree.rb', line 45

def last_idx
  @array.size - 1 unless @array.empty?
end

#popObject


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# File 'lib/compsci/complete_tree.rb', line 37

def pop
  @array.pop
end

#push(val) ⇒ Object


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# File 'lib/compsci/complete_tree.rb', line 33

def push val
  @array.push val
end

#sizeObject


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# File 'lib/compsci/complete_tree.rb', line 41

def size
  @array.size
end