List down  all data structures that you have used to store data in your projects.

Sure, here are some of the data structures I have used in my projects:

1. Arrays: I have used arrays to store and access elements in a sequential manner. They are useful when the size of the data is known.

2. Linked Lists: I have used linked lists when the size of the data is not known in advance. They allow for efficient insertion and deletion of elements.

3. Stacks: I have used stacks in projects where I needed to keep track of the order of operations, such as in a calculator application.

4. Queues: I have used queues in projects that required a first-in, first-out (FIFO) data structure, such as in a print spooler simulation.

5. Trees: I have used trees in projects that required a hierarchical structure, such as in a file system simulation.

6. Graphs: I have used graphs in projects that required representing relationships between pairs of elements, such as in a social network simulation.

7. Hash Tables: I have used hash tables in projects that required fast access to data, such as in a dictionary application.

8. Heaps: I have used heaps in projects that required efficient access to the maximum or minimum element, such as in a priority queue implementation.

9. Sets: I have used sets in projects that required storing unique elements, such as in a database of student IDs.

10. Tuples: I have used tuples in projects that required storing multiple data types together, such as in a database of student records.

11. Dictionaries: I have used dictionaries in projects that required key-value pairs, such as in a phone book application.