Class mxUnionFind

java.lang.Object
com.mxgraph.analysis.mxUnionFind

public class mxUnionFind extends Object
Implements a union find structure that uses union by rank and path compression. The union by rank guarantees worst case find time of O(log N), while Tarjan shows that in combination with path compression (halving) the average time for an arbitrary sequence of m >= n operations is O(m*alpha(m,n)), where alpha is the inverse of the Ackermann function, defined as follows: alpha(m,n) = min{i >= 1 | A(i, floor(m/n)) > log n} for m >= n >= 1 Which yields almost constant time for each individual operation.
  • Field Details

  • Constructor Details

    • mxUnionFind

      public mxUnionFind(Object[] elements)
      Constructs a union find structure and initializes it with the specified elements.
      Parameters:
      elements -
  • Method Details

    • getNode

      public mxUnionFind.Node getNode(Object element)
      Returns the node that represents element.
    • find

      public mxUnionFind.Node find(mxUnionFind.Node node)
      Returns the set that contains node. This implementation provides path compression by halving.
    • union

      public void union(mxUnionFind.Node a, mxUnionFind.Node b)
      Unifies the sets a and b in constant time using a union by rank on the tree size.
    • differ

      public boolean differ(Object a, Object b)
      Returns true if element a and element b are not in the same set. This uses getNode and then find to determine the elements set.
      Parameters:
      a - The first element to compare.
      b - The second element to compare.
      Returns:
      Returns true if a and b are in the same set.
      See Also: