Added problem "counting".

Some other small text corrections.

1 files changed, 13 insertions, 7 deletions

diff --git a/python/problems/while_and_if/consumers_anonymous/common.py b/python/problems/while_and_if/consumers_anonymous/common.py
index ff3f928..07a0ebf 100644
--- a/python/problems/while_and_if/consumers_anonymous/common.py
+++ b/python/problems/while_and_if/consumers_anonymous/common.py
@@ -32,6 +32,7 @@ hint_type = {
     'final_hint': Hint('final_hint'),
     'summation': Hint('summation'),
     'counting': Hint('counting'),
+    'counting_with_0': Hint('counting_with_0'),
     'problematic_test_case': Hint('problematic_test_case'),
 }
 
@@ -53,7 +54,8 @@ def test(python, code):
         (105, 3),
         (10, 10),
         (10, 10),
-        (9, 9)
+        (9, 9),
+        (0, 0)
     ]
 
     # List of outputs: (expression result, stdout, stderr, exception).
@@ -114,14 +116,18 @@ def hint(python, code):
 
     # student's answer is not correct (three possibilities)
     if not string_almost_equal(answer[0][1], 15) or \
-       not string_almost_equal(answer[0][2], 105) or \
-       not string_almost_equal(answer[0][3], 20):
+       not string_almost_equal(answer[1][1], 105) or \
+       not string_almost_equal(answer[2][1], 20):
         return [{'id' : 'summation'}]
 
-    # student's answer is not correct (three possibilities)
-    if not string_almost_equal(answer[0][1], 2) or \
-       not string_almost_equal(answer[0][2], 3) or \
-       not string_almost_equal(answer[0][3], 10):
+    # student's counting of items, when last price iz zero is incorrect
+    if not string_almost_equal(answer[0][1], 2) and \
+       string_almost_equal(answer[0][1], 3):
+        return [{'id' : 'counting_with_0'}]
+
+    # counting in general is incorrect
+    if not string_almost_equal(answer[1][1], 3) or \
+       not string_almost_equal(answer[2][1], 10):
         return [{'id' : 'counting'}]
 
     return None