Package com.google.javascript.jscomp.graph

Class StandardUnionFind<E>

  • Type Parameters:
    E - element type
    All Implemented Interfaces:
    UnionFind<E>, java.io.Serializable
    @GwtCompatible
public class StandardUnionFind<E>
extends java.lang.Object
implements java.io.Serializable, UnionFind<E>
    A Union-Find implementation.

    This class implements Union-Find algorithm with rank and path compression.

    See algorithmist for more detail.

    See Also:
    Serialized Form

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(@Nullable E e)
      Adds the given element to a new set if it is not already in a set.
      void addAll​(java.lang.Iterable<E> es)  
      com.google.common.collect.ImmutableList<com.google.common.collect.ImmutableSet<E>> allEquivalenceClasses()
      Returns an immutable collection containing all equivalence classes.
      com.google.common.collect.ImmutableSet<E> allRepresentatives()
      Return the reprsentative elements of all the equivalence classes.
      boolean areEquivalent​(@Nullable E a, @Nullable E b)
      Returns true if a and b belong to the same equivalence class.
      java.util.Set<E> elements()
      Returns an unmodifiable set of all elements added to the UnionFind.
      E find​(@Nullable E e)
      Returns the representative of the equivalence class of e.
      java.util.Set<E> findAll​(@Nullable E value)
      Returns the elements in the same equivalence class as value.
      E union​(@Nullable E a, @Nullable E b)
      Unions the equivalence classes of a and b and returns the representative of the resulting equivalence class.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • StandardUnionFind

        public StandardUnionFind()
        Creates an empty UnionFind structure.

      • StandardUnionFind

        public StandardUnionFind​(UnionFind<E> other)
        Creates an UnionFind structure being a copy of other structure. The created structure is optimal in a sense that the paths to the root from any element will have a length of at most 1.
        Parameters:
        other - structure to be copied

    • Method Detail

      • add

        public void add​(@Nullable E e)
        Description copied from interface: UnionFind
        Adds the given element to a new set if it is not already in a set.
        Specified by:
        add in interface UnionFind<E>

      • addAll

        public void addAll​(java.lang.Iterable<E> es)

      • union

        @CanIgnoreReturnValue
public E union​(@Nullable E a,
               @Nullable E b)
        Description copied from interface: UnionFind
        Unions the equivalence classes of a and b and returns the representative of the resulting equivalence class. The elements will be added if they are not already present.
        Specified by:
        union in interface UnionFind<E>

      • find

        public E find​(@Nullable E e)
        Description copied from interface: UnionFind
        Returns the representative of the equivalence class of e.
        Specified by:
        find in interface UnionFind<E>

      • areEquivalent

        public boolean areEquivalent​(@Nullable E a,
                             @Nullable E b)
        Description copied from interface: UnionFind
        Returns true if a and b belong to the same equivalence class.
        Specified by:
        areEquivalent in interface UnionFind<E>

      • elements

        public java.util.Set<E> elements()
        Description copied from interface: UnionFind
        Returns an unmodifiable set of all elements added to the UnionFind.
        Specified by:
        elements in interface UnionFind<E>

      • allEquivalenceClasses

        public com.google.common.collect.ImmutableList<com.google.common.collect.ImmutableSet<E>> allEquivalenceClasses()
        Description copied from interface: UnionFind
        Returns an immutable collection containing all equivalence classes. The returned collection represents a snapshot of the current state and will not reflect changes made to the data structure.
        Specified by:
        allEquivalenceClasses in interface UnionFind<E>

      • allRepresentatives

        public com.google.common.collect.ImmutableSet<E> allRepresentatives()
        Return the reprsentative elements of all the equivalence classes.

        This is a "snapshot" view of the representatives at the time the method was called.

      • findAll

        public java.util.Set<E> findAll​(@Nullable E value)
        Description copied from interface: UnionFind
        Returns the elements in the same equivalence class as value.
        Specified by:
        findAll in interface UnionFind<E>
        Returns:
        an unmodifiable view. As equivalence classes are merged, this set will reflect those changes.