Fibonacci benchmarking

This small script benchmarks four methods to compute Fibonacci numbers and plots the timings:

• naive recursive
• recursive with memoization (top-down DP)
• bottom-up iterative (array-like)
• matrix exponentiation (O(log n))

Usage

Run the script with n values you want to test:

python3 fib_bench.py 5 10 20 30 35 --output fib_times.png

Notes

• The naive recursive method is exponential and will become infeasible quickly. By default the script skips running naive recursion for n > 35; use --allow-slow to force running it for larger n (not recommended).
• The script saves a PNG plot (default fib_bench.png) showing timing lines for each method.