Logic Building/Phase 3 - Level 1: Basic Recursion/Program

Factorial Using Recursion

Calculate factorial recursively.

Logic BuildingIntermediate
Logic Building
def factorial(n):
    # Base case
    if n == 0 or n == 1:
        return 1
    
    # Recursive case
    return n * factorial(n - 1)

# Test
n = int(input("Enter n: "))
result = factorial(n)
print(f"Factorial of {n} is {result}")

Output

Enter n: 5
Factorial of 5 is 120

Factorial(n) = n * Factorial(n-1).

Key Concepts:

  • Base case: factorial(0) = factorial(1) = 1
  • Recursive case: n * factorial(n-1)
  • Function calls itself with n-1
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