# A-level Computing/AQA/Paper 1/Fundamentals of algorithms

< A-level Computing | AQA | Paper 1

In this unit you will see several algorithms that operate on the data structures you have seen in the previous unit.

- Graph traversal algorithms systematically visit all the vertices in a graph
- Tree traversal algorithms systematically visit all nodes in a tree
- Reverse Polish notation, an alternative way to represent arithmetic expressions, requires stacks or trees
- Searching algorithms check if a given data item exists in a data structure or not
- Sorting algorithms put a collection (typically an array) of items in ascending or descending order
- Optimisation Algorithms find the best solution to a problem, e.g. the shortest path from one graph vertex to another