Question

A few examples:

• “ilikestackoverflow” would match “i like stackoverflow”
• “thisisanotherexample” would match “this is another example”

I realize I could remove the spaces on the right hand to match the left hand, but I would save significant space and processing time by being able to go from left to right.

Answer 1

It would only be quicker to remove the spaces on the right side than having the regex parser (something like a state machine) trying every single combination and backtracing everytime.

Does A BC match ABC?

The regexp could be ^A\s?B\s?C$

1. Do I have an A first? yes go on
2. Do I have a space? yes go on
3. Do I have a B? yes go on
4. Do I have a space? no skip (because of the ? meaning 0 or 1)
5. Do I have a C? yes go on
6. Am I at the end of the string? yes where are done here.

Comparing two strings is much, much lighter and will be faster.