examples/fibonacci_functions.py

"""
Fibonacci computation functions for testing function analysis.
"""

def fibonacci_recursive(n):
    """Calculate fibonacci number using recursion."""
    if n <= 1:
        return n
    return fibonacci_recursive(n - 1) + fibonacci_recursive(n - 2)


def fibonacci_iterative(n):
    """Calculate fibonacci number using iteration."""
    if n <= 1:
        return n
    
    a, b = 0, 1
    for _ in range(2, n + 1):
        a, b = b, a + b
    return b


def fibonacci_memoized(n, memo=None):
    """Calculate fibonacci number using memoization."""
    if memo is None:
        memo = {}
    
    if n in memo:
        return memo[n]
    
    if n <= 1:
        memo[n] = n
        return n
    
    memo[n] = fibonacci_memoized(n - 1, memo) + fibonacci_memoized(n - 2, memo)
    return memo[n]


def fibonacci_sequence(count):
    """Generate a sequence of fibonacci numbers."""
    sequence = []
    for i in range(count):
        sequence.append(fibonacci_iterative(i))
    return sequence


def compare_fibonacci_methods(n):
    """Compare different fibonacci calculation methods."""
    import time
    
    methods = [
        ("Recursive", fibonacci_recursive),
        ("Iterative", fibonacci_iterative), 
        ("Memoized", fibonacci_memoized)
    ]
    
    results = {}
    for name, func in methods:
        start_time = time.time()
        result = func(n)
        end_time = time.time()
        results[name] = {
            'result': result,
            'time': end_time - start_time
        }
    
    return results


def validate_fibonacci_result(n, result):
    """Validate if a fibonacci result is correct."""
    if n <= 1:
        return result == n
    
    # Use iterative method as baseline for validation
    expected = fibonacci_iterative(n)
    return result == expected


if __name__ == "__main__":
    n = 10
    print(f"Fibonacci({n}) using different methods:")
    
    results = compare_fibonacci_methods(n)
    for method, data in results.items():
        print(f"{method}: {data['result']} (took {data['time']:.6f} seconds)")
    
    print(f"\nFirst 15 fibonacci numbers: {fibonacci_sequence(15)}")