# HG changeset patch
# User Eugen Sawin <sawine@me73.com>
# Date 1299335235 -3600
# Node ID 3789f490c8f38aee30988710f5156e5c056d62b3
# Parent  e088ae08440c587304ae602ea2d4d5c6e178cada
Added (DP) Fibonacci example.

diff -r e088ae08440c -r 3789f490c8f3 examples/fib.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/fib.py	Sat Mar 05 15:27:15 2011 +0100
@@ -0,0 +1,40 @@
+"""
+Name: fib - Fibonacci number machine
+Description: Recursive and DP-based calculation of Fibonacci numbers.
+
+Author: Eugen Sawin <sawine@me73.com>
+"""
+
+def main():
+    args = parse_args()
+    if args.d:
+        fun = fib_dynamic
+    else:
+        fun = fib
+    print fun(args.n)
+
+def fib(n):
+    if n > 1:
+        return fib(n-1) + fib(n-2)
+    else:
+        return n
+
+def fib_dynamic(n):
+    f = (0, 1)
+    for i in xrange(2, n + 1):
+        f = (f[1], sum(f))
+    if n < 1:
+        return n
+    else:
+        return f[1]
+
+from argparse import ArgumentParser
+
+def parse_args():
+    parser = ArgumentParser(description='Returns the Fibonacci number for a given number n.')
+    parser.add_argument('n', type=int, help='Fib(n)')
+    parser.add_argument('-d', action='store_true', help='dynamic programming')
+    return parser.parse_args()
+
+if __name__ == "__main__":
+    main()