Counting Steps: Measuring Algorithm Efficiency

Learning Objectives Define an algorithm's 'step' as a single action. Count the total number of steps in a simple, sequential algorithm. By the end of a this lesson, students will be able to explain that fewer steps usually means a faster, more 'efficient' algorithm. Count the steps in an algorithm that uses a simple loop. Compare two different algorithms for the same task and identify which one is more efficient by counting their steps. Identify the 'worst-case' number of steps for a searching algorithm. Imagine you have to find your favorite red sock in a drawer full of socks. What's the fastest way to do it? 🧦 Let's find out by counting our steps! In this lesson, we'll learn how to measure how fast our computer programs a...

TermDefinitionExample AlgorithmA list of step-by-step instructions to finish a task, just like a recipe for baking cookies.An algorithm to make a peanut butter sandwich: 1. Get two slices of bread. 2. Spread peanut butter on one slice. 3. Put the slices together. StepA single action or instruction in an algorithm.In a robot's algorithm, 'move forward one space' is one step. 'Turn right' is another single step. EfficiencyA measure of how fast an algorithm is. An algorithm with fewer steps is more efficient.An algorithm with 5 steps is more efficient than an algorithm with 20 steps to do the same job. InputThe information or items an algorithm starts with to do its job.If our algorithm is to find the tallest person in a class, the 'input' is the list of al...

The One-Action Rule 1 Action = 1 Step Every single, simple command in an algorithm counts as one step. Use this to count the total work your algorithm does. The Loop Rule Steps Inside Loop x Number of Repeats To find the total steps for a loop, count the number of actions *inside* the loop, and then multiply that by how many times the loop repeats. The Efficiency Rule Fewer Steps = More Efficient When comparing two algorithms that solve the same problem, the one that takes fewer steps in the worst-case is considered more efficient.