Prefix Search Engine

A highly optimized search engine built in C# to filter strings from datasets based on word prefixes. Developed to practice OOP, complex data structures, and algorithms.

Cool Features

Prefix Tree (Trie)

Utilizes a custom Trie data structure for very fast, memory efficient prefix lookups. Indexing time complexity is O(N) (where N is the total number of characters in the dataset).

Space Tokenization

Datasets are separated into searchable words based on spaces.

Composite Design Pattern

The architecture allows chaining an infinite number of logical filters (AndOperator, OrOperator, WordFilter) into a single query tree.

Current Operators

AND (&&)

Returns entries containing both prefix conditions (uses set intersection).

OR (||)

Returns entries containing at least one prefix condition (uses set union).

Example Usage

Dataset

"Today is Sunday"
"Today is not Monday"
"Tomorrow is Tuesday"
"Tomorrow isn’t Wednesday"
"Today is Sunday"

Query

Applying the condition Tod && Sun using the AndOperator to search for words starting with those prefixes.

Result

"Today is Sunday"