Question

So I have a LinkedHashSet , with values say a1, a2, , b, c1, c2

I want to replace, b with x , such that the order of x should be same as order of b.

One obvious way would be

 private LinkedHashSet<String> orderedSubstitution(final Set<String> originalOrderedSet, final String oldItem,
            final String newItem) {
        final LinkedHashSet<String> newOrderedSet = new LinkedHashSet<String>();
        // Things we do to maintain order in a linkedHashSet
        for (final String stringItem : originalOrderedSet) {
            if (stringItem.equals(oldItem)) {
                newOrderedSet.add(newItem);
            } else {
                newOrderedSet.add(stringItem);
            }
        }
        return newOrderedSet;
    }

not only this is O(n) i also feel this is not the fastest way. Any better solution ?
NOTE : I HAVE TO use linkedHashMap.

Answer 1

1. Create a structure Map
2. Insert all the string with < String, OrderOfTheString>
3. Do the insertion of the new String by adding a small Delta after the current string’s OrderOfTheString.
4. Convert Map to LikedHashSet

I know it is complicated but it is definately better when we have linked hash Map of ~1000000 elements and there are about 1000 elements to be inserted.