@Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            Index index = (Index) o;

            if (currentVertex != index.currentVertex) return false;
            return !(vertexSet != null ? !vertexSet.equals(index.vertexSet) : index.vertexSet != null);
        }
Date 11/17/2015
@author Tushar Roy

Help Karp method of finding tour of traveling salesman.

Time complexity - O(2^n * n^2)
Space complexity - O(2^n)

https://en.wikipedia.org/wiki/Held%E2%80%93Karp_algorithm
src/com/interview/graph/TravelingSalesmanHeldKarp.java