# Algorithms are recipes An **algorithm** is a clear list of steps to solve a problem. ## Maggi algorithm 1. Boil water 2. Add noodles 3. Add tastemaker 4. Cook 2 minutes 5. Serve If you skip step 1, dinner fails. Computers are the same — they follow the steps they are given, even silly ones. ## Good algorithms - **Clear** — no confusing words - **Finite** — they finish - **Correct** — they solve the real problem - **Efficient** — not 100 extra useless steps ## Daily algorithms Tying shoes, logging into email, finding the smallest number in a list. > Coding is writing algorithms in a language a computer understands. ## Three tests of a good algorithm 1. **Clear** — a new student could follow it 2. **Ordered** — step 3 depends on step 2 being done 3. **Finite** — it stops ### From English to code Later, each English step becomes one or two lines of Python. If the English is muddy, the code will be muddy. That is why we practise algorithms in words first. ### Pseudocode Teachers sometimes ask for **pseudocode** — English written in code-shaped lines: ``` START input marks if marks >= 40 then output "Pass" else output "Try again" end if STOP ``` You will meet this shape again in If/else.