Recursion Base Case and Recursive Case in DSA C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the base case in recursion?

The base case is the condition that stops the recursion. It prevents infinite calls by providing a simple answer without further recursion.

beginner

What is the recursive case in recursion?

The recursive case is where the function calls itself with a smaller or simpler input, moving towards the base case.

beginner

Why do we need both base case and recursive case in a recursive function?

The base case stops the recursion to avoid infinite loops, and the recursive case breaks the problem into smaller parts to solve it step by step.

beginner

Consider this C function snippet:<br>

int factorial(int n) {<br>  if (n == 0) return 1;<br>  else return n * factorial(n - 1);<br>}

<br>Identify the base case and recursive case.

Base case: if (n == 0) return 1;<br>Recursive case: return n * factorial(n - 1);

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What happens if a recursive function has no base case?

The function will keep calling itself forever, causing a stack overflow error and crashing the program.

In recursion, what is the purpose of the base case?

A To increase the input size

B To call the function again

C To stop the recursion

D To print the result

The base case stops the recursion by providing a simple answer without further calls.

Which part of a recursive function calls itself with a smaller input?

A Base case

B Return statement

C Main function

D Recursive case

The recursive case calls the function itself with a smaller or simpler input.

What will happen if a recursive function lacks a base case?

A It will run forever causing a crash

B It will print an error message

C It will return zero

D It will stop immediately

Without a base case, recursion never stops, causing a stack overflow and crash.

In the factorial function, what is the base case?

A n == 0

B n > 0

C n == 1

D n < 0

The base case is when n equals 0, returning 1 to stop recursion.

Why is the recursive case important?

A It stops the recursion

B It breaks the problem into smaller parts

C It prints the output

D It initializes variables

The recursive case breaks the problem into smaller parts to solve it step by step.

Explain in your own words what the base case and recursive case are in recursion.

Think about how recursion stops and how it keeps going.

Describe what would happen if a recursive function does not have a base case.

Imagine calling a function again and again without stopping.