Graphs Revision

4. contains one-way edges
5. removing a value from a stack
6. an abstract data type that serves as a collection of elements. Last In First Out(LIFO) structure
8. looking at the top value of a stack without removing it
10. add an element to queue
11. when 2 keys make the same hash
14. a graphs where edges have values
15. an abstract data type that holds an ordered, linear sequence of items. You can describe it as a first in, first out (FIFO) structure
16. connects vertices on a graph
18. graph with no directed edges
20. an abstract data type that can be used to represent complex non linear relationships between objects

1. linear data structure, in which the elements are not stored at contiguous memory locations
2. the front index set to 0, the rear index is set to -1
3. item being hashed
7. reuses the empty slots at the front of the array that are caused when elements are removed from the queue
9. a vertex on a graph
12. encapsulating the data and methods within a class definition
13. return an element from the front of the queue
17. a shortest path finding algorithm
19. add a value to a stack