Logic Building/Phase 3 - Level 2: Advanced Recursion/Program

Convert Number to Binary Recursively

Convert decimal number to binary recursively.

Logic BuildingIntermediate
Logic Building
def to_binary(n):
    # Base case
    if n == 0:
        return ""
    
    # Recursive case
    return to_binary(n // 2) + str(n % 2)

# Test
num = int(input("Enter a number: "))
binary = to_binary(abs(num))
if binary == "":
    binary = "0"
print(f"Binary: {binary}")

Output

Enter a number: 10
Binary: 1010

Build binary from right to left.

Key Concepts:

  • Base case: n == 0, return empty
  • Get remainder (binary digit)
  • Recurse on quotient
  • Concatenate results
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