Class AbstractGraph<N>

    • Method Detail

      • equals

        public final boolean equals​(@CheckForNull
                                    Object obj)
        Description copied from class: java.lang.Object
        Indicates whether some other object is "equal to" this one.

        The equals method implements an equivalence relation on non-null object references:

        • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
        • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
        • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
        • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
        • For any non-null reference value x, x.equals(null) should return false.

        The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

        Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

        Specified by:
        equals in interface Graph<N>
        equals in class Object
        obj - the reference object with which to compare.
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap
      • hashCode

        public final int hashCode()
        Description copied from class: java.lang.Object
        Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

        The general contract of hashCode is:

        • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
        • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
        • It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

        As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

        Specified by:
        hashCode in interface Graph<N>
        hashCode in class Object
        a hash code value for this object.
        See Also:
        Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
      • toString

        public String toString()
        Returns a string representation of this graph.
        toString in class Object
        a string representation of the object.
      • edgeCount

        protected long edgeCount()
        Returns the number of edges in this graph; used to calculate the size of edges(). This implementation requires O(|N|) time. Classes extending this one may manually keep track of the number of edges as the graph is updated, and override this method for better performance.
      • incidentEdgeOrder

        public ElementOrder<N> incidentEdgeOrder()
      • degree

        public int degree​(N node)
      • inDegree

        public int inDegree​(N node)
      • outDegree

        public int outDegree​(N node)
      • hasEdgeConnecting

        public boolean hasEdgeConnecting​(N nodeU,
                                         N nodeV)
      • hasEdgeConnecting

        public boolean hasEdgeConnecting​(EndpointPair<N> endpoints)
      • validateEndpoints

        protected final void validateEndpoints​(EndpointPair<?> endpoints)
        Throws IllegalArgumentException if the ordering of endpoints is not compatible with the directionality of this graph.
      • isOrderingCompatible

        protected final boolean isOrderingCompatible​(EndpointPair<?> endpoints)