spark: add fibonacci calculator utility

wizard-work/spark/fib_calc_new.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+"""Fibonacci calculator - computes nth Fibonacci number."""
+
+import sys
+
+
+def fibonacci(n: int) -> int:
+    """Return the nth Fibonacci number (0-indexed)."""
+    if n < 0:
+        raise ValueError("n must be non-negative")
+    if n == 0:
+        return 0
+    if n == 1:
+        return 1
+    
+    a, b = 0, 1
+    for _ in range(2, n + 1):
+        a, b = b, a + b
+    return b
+
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: fib_calc.py <n>", file=sys.stderr)
+        sys.exit(1)
+    
+    n = int(sys.argv[1])
+    result = fibonacci(n)
+    print(f"fib({n}) = {result}")
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()