Class AbstractRadixAddressableHeap<K,​V>

    • Field Detail

      • EMPTY

        protected static final int EMPTY
        Denotes that a key does not belong to a bucket
        See Also:
        Constant Field Values
      • size

        protected long size
        Number of elements
      • lastDeletedKey

        protected K lastDeletedKey
        Last deleted key. This value is used to distribute elements in the buckets. Should be initialized with the minKey value.
      • minKey

        protected K minKey
        Minimum key allowed
      • maxKey

        protected K maxKey
        Maximum key allowed
    • Constructor Detail

      • AbstractRadixAddressableHeap

        AbstractRadixAddressableHeap()
        Constructor
    • Method Detail

      • insert

        public AddressableHeap.Handle<K,​V> insert​(K key)
        Insert a new element into the heap with a null value.
        Specified by:
        insert in interface AddressableHeap<K,​V>
        Parameters:
        key - the element's key
        Returns:
        a handle for the newly added element
        Throws:
        java.lang.IllegalArgumentException - if the key is null
        java.lang.IllegalArgumentException - if the key is less than the minimum allowed key
        java.lang.IllegalArgumentException - if the key is more than the maximum allowed key
        java.lang.IllegalArgumentException - if the key is less than the last deleted key (or the minimum key allowed if no key has been deleted)
      • insert

        public AddressableHeap.Handle<K,​V> insert​(K key,
                                                        V value)
        Insert a new element into the heap.
        Specified by:
        insert in interface AddressableHeap<K,​V>
        Parameters:
        key - the element's key
        value - the element's value
        Returns:
        a handle for the newly added element
        Throws:
        java.lang.IllegalArgumentException - if the key is null
        java.lang.IllegalArgumentException - if the key is less than the minimum allowed key
        java.lang.IllegalArgumentException - if the key is more than the maximum allowed key
        java.lang.IllegalArgumentException - if the key is less than the last deleted key (or the minimum key allowed if no key has been deleted)
      • deleteMin

        public AddressableHeap.Handle<K,​V> deleteMin()
        Delete and return an element with the minimum key. If multiple such elements exists, only one of them will be deleted. After the element is deleted the handle is invalidated and only method AddressableHeap.Handle.getKey() and AddressableHeap.Handle.getValue() can be used. The cost of this operation is amortized O(logC) assuming the heap contains keys in the range [0, C] or equivalently [a, a+C].
        Specified by:
        deleteMin in interface AddressableHeap<K,​V>
        Returns:
        a handle to the deleted element with minimum key
      • isEmpty

        public boolean isEmpty()
        Returns true if this heap is empty.
        Specified by:
        isEmpty in interface AddressableHeap<K,​V>
        Returns:
        true if this heap is empty, false otherwise
      • size

        public long size()
        Returns the number of elements in the heap.
        Specified by:
        size in interface AddressableHeap<K,​V>
        Returns:
        the number of elements in the heap
      • comparator

        public java.util.Comparator<? super K> comparator()
        Always returns null since this heap uses the natural ordering of its keys.
        Specified by:
        comparator in interface AddressableHeap<K,​V>
        Returns:
        null since this heap uses the natural ordering of its keys
      • compare

        protected abstract int compare​(K o1,
                                       K o2)
        Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
        Parameters:
        o1 - the first object to be compared.
        o2 - the second object to be compared.
        Returns:
        a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
      • computeBucket

        protected int computeBucket​(K key,
                                    K minKey)
        Compute the bucket of a key based on a minimum key.
        Parameters:
        key - the key
        minKey - the minimum key
        Returns:
        the bucket where the key should go
      • msd

        protected abstract int msd​(K a,
                                   K b)
        Compute the most significant digit which is different in the binary representation of two values, or -1 if numbers are equal.
        Parameters:
        a - the first value
        b - the second value
        Returns:
        the most significant digit which is different or -1 if numbers are equal
      • findAndCacheMinimum

        private void findAndCacheMinimum​(int firstBucket)
        Helper method for finding and caching the minimum. Assumes that the heap contains at least one element.
        Parameters:
        firstBucket - start looking for elements from this bucket