[Swift]有用的Binary Heap Type类

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上代码：

/* Binary Heap Type */

open class BinaryHeap< Type >
{
    /* Heap Array */
    private var heapArray: [ Type ]
    
    /* In Order Function */
    private let inOrder: ( _ a: Type, _ b: Type ) -> Bool
    
    /* Initializer */
    
    public init( _ inOrder: @escaping ( _ a: Type, _ b: Type ) -> Bool )
    {    
        self.heapArray = [ Type ]()        
        self.inOrder = inOrder    
    }
    
    /* Get Size */
    
    open func getSize() -> Int
    {    
        return ( heapArray.count )    
    }
    
    /* Get Tale */
    
    private func getTale() -> Int
    {        
        return ( heapArray.count - 1 )    
    }
    
    /* Get Parent */
    
    private func getParent( _ nodePosition: Int ) -> Int?
    {        
        if nodePosition <= 0
        {
            return nil
        }        
        let parentPosition: Int = ( ( nodePosition - 1 ) / 2 )        
        return parentPosition    
    }
    
    /* Get Left Child */
    
    private func getLeftChild( _ nodePosition: Int ) -> Int?
    {        
        let childPosition = ( nodePosition * 2 ) + 1        
        if childPosition <= getTale()
        {
            return childPosition
        }
        else
        {
            return nil
        }        
    }
    
    /* Get Right Child */
    
    private func getRightChild( _ nodePosition: Int ) -> Int?
    {        
        let childPosition = ( nodePosition * 2 ) + 2        
        if childPosition <= getTale()
        {
            return childPosition
        }
        else
        {
            return nil
        }        
    }
    
    /* Insert Element */
    
    open func insertElement( _ element: Type )
    {    
        heapArray.append( element )        
        var traversal1 = getTale()
        var goingUp = true        
        while goingUp
        {        
            if let parent = getParent( traversal1 )
            {            
                if( !inOrder( heapArray[ parent ], heapArray[ traversal1 ] ) )
                {                
                    let temp = heapArray[ traversal1 ]
                    heapArray[ traversal1 ] = heapArray[ parent ]
                    heapArray[ parent ] = temp                    
                    traversal1 = parent                    
                }
                else
                {
                    goingUp = false
                }            
            }
            else
            {
                goingUp = false
            }        
        }    
    }
    
    /* Get Top Element */    
    open func getTopElement() -> Type?
    {    
        if getSize() == 0
        {
            return nil
        }
        else
        {
            return heapArray[ 0 ]
        }    
    }
    
    /* Delete Top Element */    
    open func deleteTopElement() -> Type?
    {    
        if getSize() == 0
        {
            return nil
        }        
        let value = getTopElement()        
        heapArray[ 0 ] = heapArray[ getTale() ]
        heapArray.removeLast()
        
        if( getSize() > 1 )
        {            
            var traversal = 0
            var goingDown = true            

            while( goingDown )
            {                
                var topChild: Int? = nil                
                if let child = getLeftChild( traversal )
                {                    
                    topChild = child                    
                }

                if let child = getRightChild( traversal )
                {                    
                    if( topChild == nil || !inOrder( heapArray[ topChild! ], heapArray[ child ] ) )
                    {                        
                        topChild = child                        
                    }                    
                }

                if( topChild != nil && !inOrder( heapArray[ traversal ], heapArray[ topChild! ] ) )
                {                    
                    let temp = heapArray[ traversal ]
                    heapArray[ traversal ] = heapArray[ topChild! ]
                    heapArray[ topChild! ] = temp
                    
                    traversal = topChild!                    
                }
                else
                {
                    goingDown = false
                }            
            }        
        }        
        return value    
    }
}

/* Array Traversal Type */

class ArrayTraversal
{    
    private let array: [ Int ]
    private var currentIndex: Int
    
    private(set) var currentValue: Int
    
    init( _ array: [ Int ] )
    {        
        self.array = array        
        self.currentIndex = 0
        
        self.currentValue = array[ currentIndex ]        
    }
    
    func getNextValue() -> Bool
    {        
        if currentIndex == ( array.count - 1 )
        {            
            return false 
        }        
        currentIndex += 1        
        currentValue = array[ currentIndex ]
        
        return true        
    }    
}