1 files changed, 30 insertions, 0 deletions
diff --git a/algorithms/inputgen.py b/algorithms/inputgen.py
new file mode 100644
index 0000000..2659ffc
--- /dev/null
+++ b/algorithms/inputgen.py
@@ -0,0 +1,30 @@
+# Copyright 2016 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is licensed under the terms of the MIT License.
+# See LICENSE.txt for details.
+
+from array import array
+from enum import Enum
+from random import seed, sample
+
+seed()
+
+class InputKind(Enum):
+    BEST, AVERAGE, WORST = 'best', 'average', 'worst'
+
+    def __str__(self):
+        return self.value
+
+def _gen_input_from(xs):
+    return array('l', xs)
+
+def gen_input_for_sorting(n, case=InputKind.AVERAGE):
+    if n < 0:
+        raise ValueError('input length must not be a negative number')
+    if case is InputKind.BEST:
+        return _gen_input_from(range(n))
+    elif case is InputKind.AVERAGE:
+        return _gen_input_from(sample(range(n), n))
+    elif case is InputKind.WORST:
+        return _gen_input_from(range(n - 1, -1, -1))
+    else:
+        raise NotImplementedError('invalid input kind: ' + str(case))