Algorithms

An algorithm is a complete, step-by-step set of instructions for completing a task, and computers must follow those instructions exactly as written. So, computers are perhaps not as intelligent as we tend to think they are!

In this section, you will not yet be implementing any specific type of algorithm (such as a sorting or searching algorithm, which we will talk about later in the course), but you will be able to express algorithms using spoken or written language, and learn of the importance of defining algorithms precisely in order to have the desired effect(s) occur!

• Lecture

  • Watch on Youtube
  • Watch on the CS50 Video Player
  • Download Lecture
  • Lecture Notes

• Notes

  • Algorithms

• Supplementary Resources

  • TED-Ed on What’s an Algorithm?
  • Big Bang Theory on The Friendship Algorithm

• Thought Questions

  • How do we know if an algorithm works?
  • What are some problems we see in the real world that require algorithmic solutions?
  • Can every problem be solved by an algorithm?
  • Add up the numbers from 1 to 100 without using a calculator. How did you do it? How long did it take? Ask a friend to do the same. Did you arrive at the same result? Did it take the same amount of time? Did your processes differ? Are both algorithms correct?

• Problem

  • Everyday Algorithms