1 files changed, 82 insertions, 0 deletions
diff --git a/python/problems/dictionaries/most_frequent/common.py b/python/problems/dictionaries/most_frequent/common.py
new file mode 100644
index 0000000..a945f1d
--- /dev/null
+++ b/python/problems/dictionaries/most_frequent/common.py
@@ -0,0 +1,82 @@
+import re
+from python.util import has_token_sequence, string_almost_equal, \
+    string_contains_number, get_tokens, get_numbers, get_exception_desc
+from server.hints import Hint
+
+id = 20604
+number = 3
+visible = True
+
+solution = '''\
+# Count number of elements in list xs.
+def freq(xs):
+    hist = {}
+    for x in xs:
+        if x not in hist:
+            hist[x] = 0
+        hist[x] += 1
+    return hist
+
+# Find element with maximal frequency
+def max_freq(f):
+    max_freq = 0
+    max_item = None
+    for item, item_freq in f.items():
+        if item_freq > max_freq:
+            max_freq = item_freq
+            max_item = item
+    return max_item
+
+def most_frequent(s):
+    return max_freq(freq(s.split())), max_freq(freq(s))
+'''
+
+hint_type = {
+    'final_hint': Hint('final_hint')
+}
+
+def test(python, code):
+    func_name = 'most_frequent'
+    tokens = get_tokens(code)
+    if not has_token_sequence(tokens, ['def', func_name]):
+        return False, [{'id' : 'no_func_name', 'args' : {'func_name' : func_name}}]
+
+    in_out = [
+        ('a', ('a', 'a')),
+        ('aa bb aa', ('aa', 'a')),
+        ('in to in ono in to smo mi', ('in', ' ')),
+        ('abc abc abc abacbca', ('abc', 'a')),
+        ('abc abc abc abacbcb', ('abc', 'b')),
+        ('abc abc abc abacbcc', ('abc', 'c')),
+    ]
+
+    test_in = [('{0}("{1}")'.format(func_name, str(l[0])), None) for l in in_out]
+    test_out = [l[1] for l in in_out]
+
+    answers = python(code=code, inputs=test_in, timeout=1.0)
+    n_correct = 0
+    tin, tout = None, None
+    for i, (ans, to) in enumerate(zip(answers, test_out)):
+        n_correct += ans[0] == to
+        if ans[0] != to:
+            tin = test_in[i][0]
+            tout = to
+
+    passed = n_correct == len(test_in)
+    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_in)}}]
+    if tin:
+        hints.append({'id': 'problematic_test_case', 'args': {'testin': str(tin), 'testout': str(tout)}})
+    if passed:
+        hints.append({'id': 'final_hint'})
+    return passed, hints
+
+
+def hint(python, code):
+    tokens = get_tokens(code)
+
+    # run one test first to see if there are any exceptions
+    answer = python(code=code, inputs=[(None, None)], timeout=1.0)
+    exc = get_exception_desc(answer[0][3])
+    if exc: return exc
+
+    return None