programming-examples/ruby/Data_Structures/binary_heap.rb
2019-11-15 12:59:38 +01:00

45 lines
971 B
Ruby

# This file contains the Ruby code from book of
# "Data Structures and Algorithms
# with Object-Oriented Design Patterns in Ruby"
# by Bruno R. Preiss.
#
# Copyright (c) 2004 by Bruno R. Preiss, P.Eng. All rights reserved.
class BinaryHeap < PriorityQueue
def enqueue(obj)
raise ContainerFull if @count == @array.length
@count += 1
i = @count
while i > 1 and @array[i/2] > obj
@array[i] = @array[i / 2]
i /= 2
end
@array[i] = obj
end
def min
raise ContainerEmpty if @count == 0
@array[1]
end
def dequeueMin
raise ContainerEmpty if @count == 0
result = @array[1]
last = @array[@count]
@count -= 1
i = 1
while 2 * i < @count + 1
child = 2 * i
if child + 1 < @count + 1 and @array[child + 1] < @array[child]
child += 1
end
break if last <= @array[child]
@array[i] = @array[child]
i = child
end
@array[i] = last
return result
end
end