SquareRootDecomposition [C]

#### This issue is about [Sqrt Decomposition](https://github.com/iiitv/algos).

- [x] Issue Title is in form `Sqrt Decomposition [C]`.
- [x] I searched or browsed the repo’s other issues to ensure this is not a duplicate.
- [x] This Algo/DS is worth adding to this repository.
- [x] Assign this issue to me (I want to work on this).
- [x] I ensure that I am not already assigned to 2 or more issues.
- [x] I will send my PR only after I'm assigned to this issue by any maintainer.
- [x] I understand that I will be unassigned from this issue if I fail to send a PR for this within a week.

The issue names Sqrt Decomposition and the repository at https://github.com/iiitv/algos, but it mentions no target file or test. Browse the repository's existing C algorithm and data-structure implementations first, then determine the project's expected location and validation approach. Done means a C implementation of Sqrt Decomposition that follows those repository conventions.

Written by the indexing model from the issue text.