Added visualization of the EEA

tikz/extended-euclidean-algorithm-runtime/eea.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+
+import csv
+
+
+def eea(a, b):
+    """
+    Calculates u*a + v*b = ggT
+    returns (ggT, u, v, steps)
+    """
+    u, v, s, t, steps = 1, 0, 0, 1, 0
+    while b > 0:
+        q = a//b
+        a, b = b, a-q*b
+        u, s = s, u-q*s
+        v, t = t, v-q*t
+        steps += 1
+    return a, u, v, steps
+
+
+def create_csv(n, filename):
+    max_steps = 0
+    with open(filename, 'wb') as csvfile:
+        csvwriter = csv.writer(csvfile, delimiter=',',
+                               quotechar='"', quoting=csv.QUOTE_MINIMAL)
+        csvwriter.writerow(["x", "y", "steps"])
+        for x in range(n):
+            for y in range(n):
+                steps = eea(x, y)[-1]
+                max_steps = max(steps, max_steps)
+                csvwriter.writerow([x, y, steps])
+    print("Maximum step number: %i" % max_steps)
+
+if __name__ == "__main__":
+    from argparse import ArgumentParser, ArgumentDefaultsHelpFormatter
+    parser = ArgumentParser(description=__doc__,
+                            formatter_class=ArgumentDefaultsHelpFormatter)
+    parser.add_argument("-n",
+                        dest="n", default=10, type=int,
+                        help="how many lines get printed")
+    args = parser.parse_args()
+    create_csv(args.n, "data.csv")