#!/usr/bin/env python3
"""
Scenario 2: Hidden Redundancy - The Memoization Problem
========================================================
This program computes Fibonacci numbers recursively.
The naive implementation has exponential time complexity due to redundant calls.

EXERCISES:
1. Run: time python3 fib_slow.py 35
2. Profile: python3 -m cProfile -s ncalls fib_slow.py 35
3. Notice the HUGE number of calls to fib()
4. See fib_cached.py for the memoized version
"""

import sys


def fib(n):
    """Compute the nth Fibonacci number recursively."""
    if n <= 1:
        return n
    return fib(n - 1) + fib(n - 2)


def main():
    n = 35  # Don't go much higher without optimization!
    if len(sys.argv) > 1:
        n = int(sys.argv[1])
    
    print(f"Computing fib({n})...")
    result = fib(n)
    print(f"fib({n}) = {result}")


if __name__ == "__main__":
    main()