problem38

problem38/problem.py

@@ -0,0 +1,58 @@
+import itertools
+
+
+def pandigital(n, multipliers):
+    for i in multipliers:
+        if i <= 0:
+            return None
+
+    return int(''.join([str(n * i) for i in multipliers]))
+
+
+def get_multipliers(n):
+    multiplier = 1
+    multipliers = []
+
+    while n * multiplier < 1000:
+        if '0' not in str(multiplier) and \
+            len(set(str(multiplier))) == len(str(multiplier)):
+            multipliers.append(multiplier)
+
+        multiplier += 1
+
+    return multipliers
+
+
+def is_pandigit_1_9(n):
+    for i in [1, 2, 3, 4, 5, 6, 7, 8, 9]:
+        if str(i) not in str(n):
+            return False
+
+    n_set = set(str(n))
+
+    return len(n_set) == len(str(n))
+
+
+def get_all_combinations(items):
+    res = []
+
+    for r in range(0, len(items) + 1):
+        for subset in itertools.combinations(items, r):
+            res.append(subset)
+
+    return filter(lambda x: len(x) > 0, res)
+
+
+def main():
+    res = []
+
+    for i in reversed(range(1, 1000)):
+        multipliers = get_multipliers(i)
+
+        for m in get_all_combinations(multipliers):
+            pandigit = pandigital(i, m)
+
+            if is_pandigit_1_9(pandigit):
+                res.append(pandigit)
+
+    return max(res)

problem38/test.py

@@ -0,0 +1,64 @@
+from problem import (
+    main, pandigital, get_multipliers, is_pandigit_1_9, get_all_combinations
+)
+
+res = main()
+
+def test_is_nine_digits_long():
+    assert len(str(res)) == 9
+
+
+def test_result_does_not_contain_zeros():
+    assert '0' not in str(res)
+
+
+def test_result_should_contain_each_number_once():
+    for i in [1, 2, 3, 4, 5, 6, 7, 8, 9]:
+        assert str(i) in str(res)
+
+
+def test_pandigital_192():
+    assert pandigital(192, [1, 2, 3]) == 192384576
+
+
+def test_pandigital_9():
+    assert pandigital(9 , [1, 2, 3, 4, 5]) == 918273645
+
+
+def test_pandigital_should_return_none_if_multiplier_lte_than_0():
+    assert pandigital(9 , [0, 1, 2, 3, 4, 5]) == None
+    assert pandigital(9 , [0, -1, 2, 3, 4, 5]) == None
+
+
+def test_get_multipliers():
+    assert get_multipliers(999) == [1]
+
+
+def test_get_multipliers_with_too_hight_number():
+    assert get_multipliers(1000) == []
+
+
+def test_is_pandigit_1_9_with_too_less_characters():
+    assert is_pandigit_1_9(111111) == False
+
+
+def test_is_pandigit_1_9_with_zero():
+    assert is_pandigit_1_9(102345678) == False
+
+
+def test_is_pandigit_1_9():
+    assert is_pandigit_1_9(123456789) == True
+
+
+def test_is_pandigit_1_9_with_double_characters():
+    assert is_pandigit_1_9(123456799) == False
+
+
+def test_get_all_combinations_123():
+    res = [(1,), (2,), (3,), (1, 2), (1, 3), (2, 3), (1, 2, 3)]
+    assert get_all_combinations([1,2, 3]) == res
+
+
+def test_get_all_combinations_12():
+    res = [(1,), (2,), (1, 2)]
+    assert get_all_combinations([1,2]) == res