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

Even Numbers 1-N Recursively

Print even numbers from 1 to n recursively.

Logic BuildingIntermediate

Logic Building

def print_even(n):
    # Base case
    if n == 0:
        return
    
    # Recursive case
    print_even(n - 1)
    # Print if even
    if n % 2 == 0:
        print(n)

# Test
n = int(input("Enter n: "))
print_even(n)

Output

Enter n: 10
2
4
6
8
10

Recurse first, then check and print if even.

Key Concepts:

Recurse to smaller problem
Check if current number is even
Print if condition met

Print N to 1 Recursively

Odd Numbers 1-N Recursively