Identifying two pointer reduction

Some problems may not fit the template for the direct application of the two-pointer pattern, but we may be able to reduce them to problems that fit the template and can be solved by directly applying the two-pointer technique. These are generally medium or hard problems as the reduction may not always be obvious, and we need to make sure the solution to the reduced problem is also the solution to the original problem.

We need to make some critical observations to determine whether the reduction is possible; asking yourself the following questions will help you determine whether a problem can be reduced to another problem solvable by directly applying a two-pointer pattern.