Recursion

Main idea

Function solves smaller version of itself until base case.

Tip

Write base case first.

Watch out

Missing base case causes crash.

Read this next

Recursion is used in many real programs. Right now you are in Advanced Engineering.

Core idea:
Function solves smaller version of itself until base case.

Read the example code on this page. Then write your own short version.

Tip:
Write base case first.

Watch out for:
Missing base case causes crash.

Your challenge:
Recursive factorial and Fibonacci.

Use the editor in the challenge lab. When your output looks correct and there is no error, press the green button to unlock the next topic.

Example code

Copy this example if it helps. Change it so it matches Recursion.

# Topic: Recursion
def main():
    sample = "edit me"
    # TODO: apply Recursion concept here
    result = sample
    print("Result:", result)

if __name__ == "__main__":
    main()

Challenge

Recursive factorial and Fibonacci.

Before you can finish: your output should include at least 16 characters; at least 1 non-empty line(s); no crash traceback—fix errors until the program runs cleanly.

Use Run. Read the output. Change your code until the task is done.

Starter reference

# Challenge starter for Recursion
def solve():
    # Write your solution here
    pass

print("Update solve() and run")

Your code

The first Run may load Python in your browser (one-time). Later runs are faster.

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