Class: DSAVisualizer::DataStructures::Queue

Inherits:
Object
  • Object
show all
Defined in:
lib/dsa_visualizer/data_structures/queue.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Queue

Returns a new instance of Queue.



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 4

def initialize
  @items = []
end

Class Method Details

.demo ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 44

def self.demo
  Visualizer.print_header("QUEUE - Core Level Visualization")
  
  Visualizer.print_section("1. Queue Concept (FIFO)")
  puts "\nFirst In, First Out - like a line at a store"
  puts "Operations: enqueue (add at rear), dequeue (remove from front)"
  
  Visualizer.print_section("2. Implementation Comparison")
  
  ruby_code = <<~RUBY
    class Queue
      def initialize
        @items = []
      end
      
      def enqueue(item)
        @items.push(item)  # O(1)
      end
      
      def dequeue
        @items.shift  # O(n) - shifts all elements!
      end
    end
  RUBY

  cpp_code = <<~CPP
    #include <queue>
    std::queue<int> q;
    
    q.push(10);   // O(1)
    q.pop();      // O(1)
    
    // Internally uses deque (double-ended queue)
    // Efficient operations at both ends
  CPP

  explanation = "Ruby's Array.shift is O(n) because it shifts all elements. C++'s std::queue uses deque internally for O(1) operations at both ends. For better Ruby performance, use a circular buffer or linked list."
  
  Visualizer.print_comparison(ruby_code, cpp_code, explanation)
  
  tracker = MemoryTracker.new
  queue = Queue.new
  
  Visualizer.print_step(1, "Enqueuing: 10, 20, 30")
  [10, 20, 30].each do |val|
    queue.enqueue(val)
    tracker.track_operation("Enqueue", "Added #{val}")
    puts queue.visualize
  end
  
  Visualizer.print_step(2, "Dequeuing")
  dequeued = queue.dequeue
  tracker.track_operation("Dequeue", "Removed #{dequeued}")
  puts "\nRemoved: #{dequeued}".colorize(:red)
  puts queue.visualize
  
  tracker.print_summary
  
  puts "\n\nšŸŽÆ Key Takeaways:".colorize(:green).bold
  puts "  1. Queue is FIFO - First In, First Out"
  puts "  2. Ruby Array.shift is O(n) - inefficient for large queues"
  puts "  3. C++ std::queue uses deque for O(1) operations"
  puts "  4. Use cases: task scheduling, BFS, buffering"
end

.learn ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 40

def self.learn
  demo
end

Instance Method Details

#dequeue ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 12

def dequeue
  @items.shift
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 20

def empty?
  @items.empty?
end

#enqueue(item) ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 8

def enqueue(item)
  @items.push(item)
end

#front ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 16

def front
  @items.first
end

#size ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 24

def size
  @items.size
end

#visualize ⇒ Object 



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# File 'lib/dsa_visualizer/data_structures/queue.rb', line 28

def visualize
  return "Empty queue" if @items.empty?
  
  result = "\nFRONT ā†’ "
  @items.each_with_index do |item, idx|
    result += "[ #{item} ]"
    result += " ā†’ " unless idx == @items.size - 1
  end
  result += " ā† REAR"
  result
end